JP4713745B2 - Authentication communication apparatus and authentication communication system - Google Patents

Description

ここで、＋は、データとデータの結合を示す演算子である。
【００６６】
次に、コンテンツ鍵生成部１１３は、生成したコンテンツ鍵ＣＫを暗号化部１１４と、暗号化部１１７とへ出力する。
（ｄ）暗号化部１１４
暗号化部１１４は、コンテンツ鍵生成部１１３からコンテンツ鍵ＣＫを受け取り、共通鍵記憶部１０４から共通鍵ＵＫを読み出し、読み出した共通鍵ＵＫを用いて、受け取ったコンテンツ鍵ＣＫに暗号化アルゴリズムＥ４を施して暗号化コンテンツ鍵ＥｎｃＣＫを生成し、生成した暗号化コンテンツ鍵ＥｎｃＣＫを暗号復号部１１６へ出力する。
【００６７】
ここで、暗号化部１１４は、暗号アルゴリズムＥ４として、ＤＥＳを用いる。
（ｅ）暗号復号部１１６
暗号復号部１１６は、暗号化部１１４から暗号化コンテンツ鍵ＥｎｃＣＫを受け取り、受け取った暗号化コンテンツ鍵ＥｎｃＣＫに、時変鍵ＶＫを用いて、暗号アルゴリズムＥ２を施してＥｎｃ（ＥｎｃＣＫ）を生成し、生成したＥｎｃ（ＥｎｃＣＫ）を暗号復号部２１１へ出力する。
【００６８】
ここで、暗号復号部１１６は、暗号アルゴリズムＥ２として、ＤＥＳを用いる。
（ｆ）暗号化部１１７
暗号化部１１７は、データ記憶部１１０からコンテンツデータＣＤを読み出し、読み出したコンテンツデータＣＤに、コンテンツ鍵ＣＫを用いて、暗号化アルゴリズムＥ５を施して暗号化コンテンツデータＥｎｃＣＤを生成する。次に、暗号化部１１７は、生成した暗号化コンテンツデータＥｎｃＣＤをデータ記憶部２１３へ出力する。
【００６９】
ここで、暗号化部１１７は、暗号アルゴリズムＥ５として、ＤＥＳを用いる。
（２）メモリカード２０ｂの構成
メモリカード２０ｂは、共通鍵記憶部２０１、乱数種記憶部２０２、乱数種更新部２０３、乱数生成部２０４、復号化部２０５、分離部２０６、相互認証部２０７、時変鍵生成部２０８、暗号復号部２１１、鍵データ記憶部２１２及びデータ記憶部２１３から構成されている。
【００７０】
以下において、メモリカード２０との相違点を中心として説明する。その他の点については、メモリカード２０と同じであるので、説明を省略している。
（ａ）時変鍵生成部２０８
時変鍵生成部２０８は、時変鍵ＶＫを暗号復号部２１１へ出力する。
（ｂ）暗号復号部２１１
暗号復号部２１１は、時変鍵生成部２０８から時変鍵ＶＫを受け取り、暗号復号部１１６からＥｎｃ（ＥｎｃＣＫ）を受け取る。
【００７１】
次に、暗号復号部２１１は、時変鍵ＶＫを用いてＥｎｃ（ＥｎｃＣＫ）に復号アルゴリズムＤ２を施して暗号化コンテンツ鍵ＥｎｃＣＫを生成し、生成した暗号化コンテンツ鍵ＥｎｃＣＫを前記アクセス情報により示される鍵データ記憶部２１２の領域に書き込む。
（ｃ）鍵データ記憶部２１２
鍵データ記憶部２１２は、暗号化コンテンツ鍵ＥｎｃＣＫを記憶する領域を備える。
【００７２】
（ｄ）データ記憶部２１３
データ記憶部２１３は、暗号化コンテンツデータＥｎｃＣＤを受け取り、受け取った暗号化コンテンツデータＥｎｃＣＤを記憶する。
６．２ 認証通信システム１００ｂの動作
認証通信システム１００ｂの動作は、認証通信システム１００ａの動作に類似している。ここでは、認証通信システム１００ａとの相違点についてのみ説明する。
【００７３】
認証通信システム１００ｂの動作は、認証通信システム１００ａの動作を示すフローチャートのうち、ステップＳ１２１以降を図１０に示すフローチャートに置き換えたフローチャートにより示される。
コンテンツ鍵生成部１１３は、コンテンツ付加情報記憶部１１５からコンテンツ付加情報を読み出し（ステップＳ３０１）、乱数生成部１１２は、生成した乱数Ｒ３をコンテンツ鍵生成部１１３へ出力し、コンテンツ鍵生成部１１３は、乱数生成部１１２からＲ３を受け取り、Ｒ３と読み出したコンテンツ付加情報を用いて、コンテンツ鍵ＣＫを生成し、生成したコンテンツ鍵ＣＫを暗号化部１１４と、暗号化部１１７とへ出力し（ステップＳ３０２）、暗号化部１１４は、コンテンツ鍵生成部１１３からコンテンツ鍵ＣＫを受け取り、共通鍵記憶部１０４から共通鍵ＵＫを読み出し、読み出した共通鍵ＵＫを用いて、受け取ったコンテンツ鍵ＣＫに暗号化アルゴリズムＥ４を施して暗号化コンテンツ鍵ＥｎｃＣＫを生成し、生成した暗号化コンテンツ鍵ＥｎｃＣＫを暗号復号部１１６へ出力する（ステップＳ３０３）。次に、暗号復号部１１６は、暗号化コンテンツ鍵ＥｎｃＣＫを受け取り、受け取った暗号化コンテンツ鍵ＥｎｃＣＫに時変鍵ＶＫを用いて暗号アルゴリズムＥ２を施してＥｎｃ（ＥｎｃＣＫ）を生成し（ステップＳ３０４）、暗号復号部１１６は、生成したＥｎｃ（ＥｎｃＣＫ）を暗号復号部２１１へ出力し、暗号復号部２１１は、Ｅｎｃ（ＥｎｃＣＫ）を受け取り（ステップＳ３０５）、暗号復号部２１１は、Ｅｎｃ（ＥｎｃＣＫ）に時変鍵ＶＫを用いて復号アルゴリズムＤ２を施して暗号化コンテンツ鍵ＥｎｃＣＫを生成し、生成した暗号化コンテンツ鍵ＥｎｃＣＫを前記アクセス情報により示される鍵データ記憶部２１２の領域に書き込む（ステップＳ３０６）。
【００７４】
暗号化部１１７は、データ記憶部１１０からコンテンツデータＣＤを読み出し（ステップＳ３０７）、読み出したコンテンツデータＣＤにコンテンツ鍵ＣＫを用いて暗号化アルゴリズムＥ５を施して暗号化コンテンツデータＥｎｃＣＤを生成する（ステップＳ３０８）。暗号化部１１７は、生成した暗号化コンテンツデータＥｎｃＣＤをデータ記憶部２１３へ出力し、データ記憶部２１３は、暗号化コンテンツデータＥｎｃＣＤを受け取り（ステップＳ３０９）、データ記憶部２１３は、受け取った暗号化コンテンツデータＥｎｃＣＤを記憶する（ステップＳ３１０）。
【００７５】
６．３ まとめ
以上説明したように、認証通信システム１００ｂにおいて、コンテンツデータを暗号化するためのコンテンツ鍵を生成するのに、新たな乱数発生機構を必要とぜす、アクセス情報の合成に用いる乱数発生機構と共有化できる。
７．その他の変形例
なお、本発明を上記の実施の形態に基づいて説明してきたが、本発明は、上記の実施の形態に限定されないのはもちろんである。以下のような場合も本発明に含まれる。
【００７６】
（１）上記の実施の形態において、デジタル著作物は、音楽の情報であるとしているが、小説や論文などの文字データ、コンピュータゲーム用のコンピュータプログラムソフトウェア、ＭＰ３などに代表される圧縮された音声データ、ＪＰＥＧなどの静止画像、ＭＰＥＧなどの動画像であるとしてもよい。
また、リーダライタ装置は、パーソナルコンピュータに限定されず、上記の様々なデジタル著作物を販売したり配布したりする出力装置であるとしてもよい。また、リーダライタ装置は、ヘッドホンステレオに限定されず、デジタル著作物を再生する再生装置であるとしてもよい。例えば、コンピュータゲーム装置、帯型情報端末、専用装置、パーソナルコンピュータなどであるとしてもよい。また、リーダライタ装置は、上記出力装置と再生装置との両方を兼ね備えているとしてもよい。
【００７７】
（２）上記の実施の形態において、暗号アルゴリズム及び復号アルゴリズムは、ＤＥＳを用いるとしているが、他の暗号を用いるとしてもよい。
また、上記実施の形態において、ＳＨＡを用いるとしているが、他の一方向性関数を用いるとしてもよい。
共通鍵、時変鍵の鍵長は、５６ビットであるとしているが、他の長さの鍵を用いるとしてもよい。
【００７８】
（３）上記の実施の形態において、合成部１０３は、アクセス情報と、乱数種の下位３２ビットとを結合して、６４ビット長の乱数化アクセス情報を生成するとしているが、これに限定されない。次のようにしてもよい。
合成部１０３は、３２ビットのアクセス情報と、乱数種の下位３２ビットとを１ビットずつ交互に結合して、６４ビット長の乱数化アクセス情報を生成していもよい。また、複数ビットずつ交互に結合してもよい。この場合、分離部２０６は、逆の操作を行うようにする。
【００７９】
（４）上記の実施の形態において、メモリカード２０の乱数生成部２０４は、乱数種記憶部２０２に記憶されている乱数種を用いて乱数Ｒ２を生成するとしているが、乱数生成部２０４は、乱数種を乱数Ｒ２として生成してもよい。
また、時変鍵生成部１０８、２０８は、Ｒ１及びＲ２を用いて時変鍵を生成するとしているが、応答値を用いるとしてもよい。また、共通鍵ＵＫを絡ませてもよい。
【００８０】
（５）認証通信システム１００ｂにおいて、暗号化部１１７は、暗号化コンテンツデータＥｎｃＣＤをデータ記憶部２１３に書き込むとしているが、暗号化コンテンツデータＥｎｃＣＤを機密データとして扱って、アクセス情報により示される領域に書き込むとしてもよい。
また、暗号化コンテンツ鍵ＥｎｃＣＫを機密データとして扱わずに、データ記憶部２１３に書き込むとしてもよい。
【００８１】
また、暗号化部１１４及び暗号化部１１７のいずれか一方を無くし、残っている一方により共有化してもよい。
（６）本発明は、上記に示す方法であるとしてもよい。また、これらの方法をコンピュータにより実現するコンピュータプログラムであるとしてもよいし、前記コンピュータプログラムからなるデジタル信号であるとしてもよい。
【００８２】
また、本発明は、前記コンピュータプログラム又は前記デジタル信号をコンピュータ読み取り可能な記録媒体、例えば、フロッピーディスク、ハードディスク、ＣＤ―ＲＯＭ、ＭＯ、ＤＶＤ、ＤＶＤ−ＲＯＭ、ＤＶＤ−ＲＡＭ、半導体メモリなど、に記録したものとしてもよい。また、これらの記録媒体に記録されている前記コンピュータプログラム又は前記デジタル信号であるとしてもよい。
【００８３】
また、本発明は、前記コンピュータプログラム又は前記デジタル信号を、電気通信回線、無線又は有線通信回線、インターネットを代表とするネットワーク等を経由して伝送するものとしてもよい。
また、本発明は、マイクロプロセッサとメモリとを備えたコンピュータシステムであって、前記メモリは、上記コンピュータプログラムを記憶しており、前記マイクロプロセッサは、前記コンピュータプログラムに従って動作するとしてもよい。
【００８４】
また、前記プログラム又は前記デジタル信号を前記記録媒体に記録して移送することにより、又は前記プログラム又は前記デジタル信号を前記ネットワーク等を経由して移送することにより、独立した他のコンピュータシステムにより実施するとしてもよい。
（４）上記実施の形態及び上記変形例をそれぞれ組み合わせるとしてもよい。
【００８５】
８．産業上の利用の可能性
デジタル著作物を出力する出力装置から半導体記録媒体へデジタル著作物を複製する場合において、出力装置と半導体記録媒体とが、相互に正当性を認証する場合に利用することができる。また、デジタル著作物の記録されている半導体記録媒体からデジタル著作物を読み出して再生する場合において、半導体記録媒体と再生装置との間で、各装置が、相互に正当性を認証する場合に利用することができる。
【００８６】
【発明の効果】
上記目的を達成するために本発明は、デジタル情報を記憶する領域を有する記録媒体と、前記領域からデジタル情報を読み出し又は前記領域へデジタル情報を書き込むアクセス装置とから構成される認証通信システムであって、前記アクセス装置から前記記録媒体へ、前記領域を示すアクセス情報を攪乱して生成した攪乱化アクセス情報を伝送し、前記攪乱化アクセス情報を用いて、前記アクセス装置がチャレンジレスポンス型の認証プロトコルによる前記記録媒体の正当性の認証を行う第１認証フェーズと、前記記録媒体が前記アクセス装置の正当性の認証を行う第２認証フェーズと、前記記録媒体と前記アクセス装置とがともに正当性を有すると認証された場合に、前記記録媒体は、前記認証プロセスにおいて用いられた攪乱化アクセス情報からアクセス情報を抽出し、前記アクセス装置は、抽出された前記アクセス情報により示される領域からデジタル情報を読み出し、又は前記アクセス情報により示される領域へデジタル情報を書き込む転送フェーズとを含むことを特徴とする。
【００８７】
これによって、相互認証と同時に、機密のデータを記録している機密データ記憶領域にアクセスするための情報を攪乱して転送するので、機密データ記憶領域にアクセスするための情報の機密性を高めることができる。
また、仮に、機密データ記憶領域にアクセスするための情報が、不正ななりすましにより、別の情報に改竄されて転送された場合であっても、相互認証が成功しないので、機密データ記憶領域にアクセスできないようにすることができる。
【図面の簡単な説明】
【図１】図１は、認証通信システム１００の具体的な構成例としての認証通信システム３０及び３１の外観を示す。図１（ａ）は、パーソナルコンピュータとメモリカード２０から構成される認証通信システム３０の外観を示し、図１（ｂ）は、ヘッドホンステレオ、メモリカード２０及びヘッドホンから構成される認証通信システム３１の外観を示す。
【図２】図２は、認証通信システム１００を構成するリーダライタ装置１０及びメモリカード２０のそれぞれ構成を示すブロック図である。
【図３】図３は、アクセス情報、乱数種及び乱数化アクセス情報のデータ構造を示す。
【図４】図４は、認証通信システム１００の動作を示すフローチャートであり、特に、メモリカードに記憶されている情報を読み出す場合を想定したものである。図５に続く。
【図５】図５は、認証通信システム１００の動作を示すフローチャートである。図４から続く。
【図６】図６は、認証通信システム１００の動作を示すフローチャートであり、特に、リーダライタ装置１０は、メモリカードに情報を書き込む装置であると想定した場合のものである。
【図７】図７は、別の実施の形態としての、認証通信システム１００ａの構成を示すブロック図である。
【図８】図８は、認証通信システム１００ａに固有の動作を示すフローチャートである。
【図９】図９は、別の実施の形態としての、認証通信システム１００ｂの構成を示すブロック図である。
【図１０】図１０は、認証通信システム１００ｂに固有の動作を示すフローチャートである。
【符号の説明】
１００ 認証通信システム
１０ リーダライタ装置
１０１ アクセス情報記憶部
１０２ 乱数種記憶部
１０３ 合成部
１０４ 共通鍵記憶部
１０５ 暗号化部
１０６ 乱数種更新部
１０７ 相互認証部
１０８ 時変鍵生成部
１０９ 暗号復号部
１１０ データ記憶部
１１１ 入出力部
２０ メモリカード
２０１ 共通鍵記憶部
２０２ 乱数種記憶部
２０３ 乱数種更新部
２０４ 乱数生成部
２０５ 復号化部
２０６ 分離部
２０７ 相互認証部
２０８ 時変鍵生成部
２０９ データ記憶部
２１０ 暗号復号部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for mutually authenticating authenticity between a device and a recording medium when a digital work is transferred between the device and the recording medium.
[0002]
[Prior art]
In recent years, with the development of digital information compression technology and the explosive spread of the global communication infrastructure represented by the Internet, copyrighted works such as music, images, videos, games, etc. are sent to each household as digital works through communication lines. Distribution is realized.
[0003]
In order to establish the distribution and distribution system to protect the rights of the copyright holders of digital works and the profits of distributors, illegal acquisition of works by intercepting communications, eavesdropping, impersonation, etc. It is a challenge to prevent illegal acts such as illegal duplication and illegal tampering from recorded recording media, such as determining whether it is a legitimate system or performing data scrambling such as encryption and authentication. Copyright protection technology is needed.
[0004]
Various copyright protection technologies have been known, and as a typical example, when accessing confidential data storage areas that store confidential data that requires protection of copyrighted work, There is a challenge-response type mutual authentication technology that exchanges random numbers and response values to mutually authenticate each other and permits access only when it is valid.
[0005]
[Problems to be solved by the invention]
However, for example, after performing mutual authentication using a legitimate device, an act of impersonating a legitimate device and accessing the confidential data storage area to illegally obtain confidential data can be considered.
Therefore, the present invention has been made in view of such problems, and records an access device, a recording medium, an authentication communication system, an authentication communication method, and an authentication communication program that do not leak information for accessing a confidential data storage area. It is an object to provide a recording medium and an authentication communication program.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a recording medium having an area for storing digital information, and digital information from the area. The An authentication communication system comprising an access device for reading or writing digital information to the area, wherein disturbed access information generated by disturbing the access information indicating the area is transmitted from the access device to the recording medium And using the disturbed access information A first authentication phase in which the access device authenticates the validity of the recording medium using a challenge-response type authentication protocol, a second authentication phase in which the recording medium authenticates the validity of the access device, and the recording When both the medium and the access device are authenticated as valid, the recording medium is Used in the authentication process Access information is extracted from disturbed access information, and the access device includes a transfer phase that reads digital information from an area indicated by the extracted access information or writes digital information to an area indicated by the access information It is characterized by that.
[0007]
Here, in the first authentication phase, the access device includes an access information acquisition unit that acquires access information indicating the area, a random number acquisition unit that acquires a random number, the acquired access information, and the acquired random number. And a generating unit that generates randomized access information and an encryption unit that generates a disturbed access information by applying a cryptographic algorithm to the generated randomized access information, and the recording medium includes the generated disturbed A response value generating unit that generates a response value from the access information, and the access device is configured to include an authentication unit that authenticates the validity of the recording medium using the generated response value. Also good.
[0008]
Here, in the transfer phase, the recording medium performs a decoding algorithm on the generated disturbed access information to generate randomized access information; and Generation And a separation unit that separates the access information from the randomized access information. Here, in the first authentication phase, the access device further includes a random number seed storage unit storing a random number seed, and the random number acquisition unit reads the random number seed from the random number seed storage unit, thereby You may comprise so that it may acquire.
[0009]
Here, in the first authentication phase, the access device may further be configured to overwrite the randomized seed storage unit with the disturbed access information as a random seed.
Here, in the first authentication phase, the access device further includes a random number seed storage unit storing a random number seed, and the random number acquisition unit reads the random number seed from the random number seed storage unit and reads the read random number You may comprise so that a random number may be acquired by producing | generating a random number based on a seed | species.
[0010]
Here, in the first authentication phase, the access device may be further configured to overwrite the generated random number as a random number seed in the random number seed storage unit.
Here, in the transfer phase, the recording medium in which the digital information is recorded in the area reads the digital information from the area indicated by the access information, and performs an encryption algorithm on the read digital information to encrypt the digital information. The access device that reads out digital information from the area includes a decryption unit that generates a digital information by applying a decryption algorithm to the generated encrypted digital information, and the decryption algorithm includes the cipher The ciphertext generated by the algorithm may be decrypted.
[0011]
Here, in the transfer phase, the access device that writes digital information to the area includes a digital information acquisition unit that acquires the digital information, and an encryption unit that generates an encrypted digital information by applying an encryption algorithm to the acquired digital information The recording medium includes a decryption unit that generates a digital information by applying a decryption algorithm to the generated encrypted digital information, and writes the digital information to the area indicated by the access information. The ciphertext generated by the encryption algorithm may be decrypted.
[0012]
Here, in the transfer phase, the access device that writes digital information to the area includes a digital information acquisition unit that acquires digital information, a content key acquisition unit that acquires a content key, and a first cipher in the acquired content key. A first encryption unit that generates an encrypted content key by applying an algorithm; a second encryption unit that generates a double encrypted content key by applying a second encryption algorithm to the generated encrypted content key; Using the content key, the obtained digital information is subjected to a second encryption algorithm to obtain an encrypted data. The And a third encryption unit that generates the total information, and the recording medium applies a first decryption algorithm to the generated double encrypted content key to generate an encrypted content key, which is indicated by the access information A decrypting unit that writes the encrypted content key to the area may be included, and the recording medium may further include an area for storing the generated encrypted digital information.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An authentication communication system 100 as one embodiment according to the present invention will be described.
1. Appearance and usage of authentication communication system 100
External views of authentication communication systems 30 and 31 as specific configuration examples of the authentication communication system 100 are shown in FIGS.
[0014]
As shown in FIG. 1A, the authentication communication system 30 includes a personal computer and a memory card 20. The personal computer includes a display unit, a keyboard, a speaker, a microprocessor, a RAM, a ROM, a hard disk unit, and the like, and is connected to a network represented by the Internet via a communication line. The memory card 20 is inserted from the memory card insertion slot and is attached to the personal computer.
[0015]
As shown in FIG. 1B, the authentication communication system 31 includes a headphone stereo, a memory card 20, and headphones. The memory card 20 is inserted from the memory card insertion slot of the headphone stereo and attached to the headphone stereo. In the headphone stereo, a plurality of operation buttons are arranged on the upper surface, and the headphones are connected to another side surface.
[0016]
The user attaches the memory card 20 to a personal computer, takes in digital works such as music from an external Web server device via the Internet, and writes the taken digital works into the memory card 20. Next, the user attaches the memory card 20 on which the digital work is recorded to the headphone stereo, and plays back and enjoys the digital work recorded on the memory card 20 with the headphone stereo.
[0017]
Here, between the personal computer and the memory card 20 and between the headphone stereo and the memory card 20, the authenticity of each device is verified by a challenge response type authentication protocol, and the devices are mutually valid. Only when it is authenticated, digital works are transferred between the devices.
2. Configuration of authentication communication system 100
The authentication communication system 100 includes a reader / writer device 10 and a memory card 20 as shown in FIG. Here, the reader / writer device 10 corresponds to the personal computer and the headphone stereo shown in FIGS.
[0018]
2.1 Configuration of Reader / Writer Device 10
The reader / writer device 10 includes an access information storage unit 101, a random number seed storage unit 102, a synthesis unit 103, a common key storage unit 104, an encryption unit 105, a random number seed update unit 106, a mutual authentication unit 107, and a time variable key generation unit 108. , An encryption / decryption unit 109, a data storage unit 110, and an input / output unit 111.
[0019]
Specifically, the reader / writer device 10 includes a microprocessor, a RAM, a ROM, and the like. A computer program is recorded in the ROM or the like, and the microprocessor operates according to the computer program.
(1) Input / output unit 111
The input / output unit 111 accepts a user's operation and generates access information for accessing music information stored in the data storage unit 209 of the memory card 20. As shown in FIG. 3, the access information has a 32-bit length and is composed of address information indicating the address of the area of the data storage unit of the memory card 20 and size information indicating the size of the area. The address information is 24 bits long, and the size information is 8 bits long.
[0020]
Further, the input / output unit 111 reads the music information CT from the data storage unit 110, converts the read music information CT into an audio signal, and outputs it.
The input / output unit 111 receives a user operation, acquires music information CT from the outside, and writes the acquired music information CT in the data storage unit 110.
(2) Access information storage unit 101
Specifically, the access information storage unit 101 is composed of a semiconductor memory and includes an area for storing access information.
[0021]
(3) Random number seed storage unit 102
Specifically, the random number seed storage unit 102 includes a semiconductor memory, and stores a 64-bit long random number seed as shown in FIG. 3 in advance. The random number seed is recorded when the device is manufactured.
The random number seed storage unit 102 does not have a means that can be directly accessed from the outside, but is a protected storage means.
[0022]
(4) Composition unit 103
The combining unit 103 reads access information from the access information storage unit 101 and reads a random number seed from the random number seed storage unit 102. Next, as shown in FIG. 3, the read access information is combined with the lower 32 bits of the read random number seed to generate 64-bit randomized access information. The generated randomized access information is output to the encryption unit 105.
[0023]
(5) Common key storage unit 104
Specifically, the common key storage unit 104 is composed of a semiconductor memory and includes an area for storing a 56-bit long common key UK. The reader / writer device 10 secretly acquires the common key UK stored in the common key storage unit 201 from the memory card 20, and the common key storage unit 104 stores the acquired common key UK.
[0024]
The common key storage unit 104 does not have a means that can be directly accessed from the outside, but is a protected storage means.
(6) Encryption unit 105
The encryption unit 105 reads the common key UK from the common key storage unit 104 and receives randomized access information from the synthesis unit 103. Next, the encryption unit 105 generates the encrypted access information R1 by applying the encryption algorithm E1 to the received randomized access information using the common key UK. Here, the encryption unit 105 uses DES (Data Encryption Standard) as the encryption algorithm E1.
[0025]
Next, the encryption unit 105 outputs the generated encrypted access information R1 to the mutual authentication unit 107, the random number seed update unit 106, and the time variable key generation unit 108. Further, the generated encrypted access information R1 is output to the decryption unit 205, the mutual authentication unit 207, and the time variable key generation unit 208 of the memory card 20.
The encrypted access information R1 generated in this way is disturbed information obtained by subjecting the access information to a scramble process.
[0026]
(7) Random number seed update unit 106
The random number seed update unit 106 receives the encrypted access information R1 from the encryption unit 105, and overwrites the received random access seed R1 as a new random number type in the random number seed storage unit 102.
(8) Mutual authentication unit 107
The mutual authentication unit 107 receives the encrypted access information R1, reads the common key UK from the common key storage unit 104, and calculates a response value V2 ′ by Equation 1 using the received R1 and the common key UK.
(Formula 1) V2 ′ = F1 (R1, UK) = SHA (R1 + UK)
Here, as an example, the function F1 (a, b) is a function that combines a and b and applies SHA (Secure Hash Algorithm) to the combined result. In addition, + is an operator which shows a coupling | bonding.
[0027]
The mutual authentication unit 107 receives the response value V2 from the mutual authentication unit 207.
Next, the mutual authentication unit 107 determines whether or not V2 and V2 ′ match. If they do not match, the mutual authentication unit 107 recognizes that the memory card 20 is an unauthorized device and Execution of subsequent operations is prohibited. If they match, the mutual authentication unit 107 recognizes that the memory card 20 is a valid device, and permits the other components to execute the subsequent operations.
[0028]
In addition, the mutual authentication unit 107 receives the random number R2 from the random number generation unit 204, calculates the response value V1 using Equation 2 using the received random number R2 and the common key UK, and calculates the calculated response value V1. Output to the mutual authentication unit 207.
(Formula 2) V1 = F2 (R2, UK) = SHA (R2 + UK)
(9) Time-varying key generation unit 108
The time-varying key generation unit 108 receives the encrypted access information R1 and the random number R2 when the memory card 20 is recognized as a valid device and the execution of the operation is permitted, and from the R1 and R2, the expression Generate time-varying key VK using 3
(Formula 3) VK = F3 (R1, R2) = SHA (R1 + R2)
Next, the time variable key generation unit 108 outputs the generated time variable key VK to the encryption / decryption unit 109.
[0029]
(10) Encryption / decryption unit 109
The encryption / decryption unit 109 receives the time variable key VK from the time variable key generation unit 108.
The encryption / decryption unit 109 receives the encrypted music information EncCT from the encryption / decryption unit 210, generates the music information CT by applying the decryption algorithm D3 to the encrypted music information EncCT using the time variable key VK, and generates the generated music Information CT is written into the data storage unit 110.
[0030]
Here, the encryption / decryption unit 109 uses DES as the decryption algorithm E3.
Further, the encryption / decryption unit 109 reads the music information CT from the data storage unit 110, generates the encrypted music information EncCT by applying the encryption algorithm E2 to the music information CT using the time-varying key VK, and generates the generated encryption The encrypted music information EncCT is output to the encryption / decryption unit 210.
[0031]
Here, the encryption / decryption unit 109 uses DES as the encryption algorithm E2.
(11) Data storage unit 110
Specifically, the data storage unit 110 is composed of a semiconductor memory and includes an area for storing music information CT.
[0032]
2.2 Memory card 20
The memory card 20 includes a common key storage unit 201, a random number seed storage unit 202, a random number seed update unit 203, a random number generation unit 204, a decryption unit 205, a separation unit 206, a mutual authentication unit 207, a time-varying key generation unit 208, data The storage unit 209 and the encryption / decryption unit 210 are configured.
[0033]
(1) Common key storage unit 201
The common key storage unit 201 is specifically composed of a semiconductor memory, and stores a 56-bit common key UK. The common key UK is recorded when the memory card 20 is manufactured.
The common key storage unit 201 does not have a means that can be directly accessed from the outside, but is a protected storage means.
[0034]
(2) Random number seed storage unit 202
Specifically, the random number seed storage unit 202 includes a semiconductor memory, and stores a 64-bit long random number seed in advance. The random number seed is recorded when the memory card 20 is manufactured.
The random number seed storage unit 202 does not have a means that can be directly accessed from the outside, but is a protected storage means.
[0035]
(3) Random number generator 204
The random number generation unit 204 reads the random number seed from the random number seed storage unit 202, generates a 64-bit long random number R2 using the read random number seed, and generates the generated random number R2 with the random number seed update unit 203 and the mutual authentication unit 207. Are output to the time variable key generation unit 208, and the generated random number R2 is output to the mutual authentication unit 107 and the time variable key generation unit 108 of the reader / writer device 10.
[0036]
(4) Random number seed update unit 203
The random number seed update unit 203 receives the random number R2 from the random number generation unit 204, and overwrites the random number seed storage unit 202 with the received random number R2 as a new random number seed.
(5) Decoding unit 205
The decryption unit 205 reads the common key UK from the common key storage unit 201 and receives the encrypted access information R1 from the encryption unit 105. Next, the decrypted algorithm D1 is applied to the received encrypted access information R1 using the read common key UK to generate randomized access information, and the generated randomized access information is output to the separation unit 206.
[0037]
Here, the decoding unit 205 uses DES as the decoding algorithm D1. The decryption algorithm D1 decrypts the ciphertext generated by the encryption algorithm E1.
(6) Separation unit 206
The separating unit 206 receives the randomized access information from the decrypting unit 205, separates the upper 32 bits of data from the received randomized access information as access information, and outputs the access information to the data storage unit 209.
[0038]
(7) Mutual authentication unit 207
The mutual authentication unit 207 reads the common key UK from the common key storage unit 201, receives the encrypted access information R1, uses the received R1 and the common key UK, calculates the response value V2 using Equation 4, and calculates The V2 is output to the mutual authentication unit 107 of the reader / writer device 10.
(Formula 4) V2 = F1 (R1, UK) = SHA (R1 + UK)
Here, F1 may be the same function as F1 shown in Expression 1.
[0039]
Also, the mutual authentication unit 207 receives the random number R2 from the random number generation unit 204, and calculates the response value V1 ′ by Equation 5 using the received random number R2 and the common key UK.
(Formula 5) V1 ′ = F2 (R2, UK) = SHA (R2 + UK)
Here, F2 may be the same function as F2 shown in Expression 2.
[0040]
Next, the mutual authentication unit 207 receives V1 from the mutual authentication unit 107, determines whether V1 and V1 ′ match, and if not, determines that the reader / writer device 10 is an unauthorized device. Accreditation is prohibited and execution of subsequent operations is prohibited for other components. If they match, the mutual authentication unit 207 recognizes that the reader / writer device 10 is a valid device, and permits the other components to execute the subsequent operations.
[0041]
(8) Time-varying key generation unit 208
The time variable key generation unit 208 receives the encrypted access information R1 and the random number R2 when the reader / writer device 10 is recognized as a valid device and the execution of the operation is permitted, and from the R1 and R2, Generate time-varying key VK using Equation 6
(Formula 6) VK = F3 (R1, R2) = SHA (R1 + R2)
Here, F3 is the same as the function F3 shown in Expression 3.
[0042]
Next, the time variable key generation unit 208 outputs the generated time variable key VK to the encryption / decryption unit 210.
(9) Data storage unit 209
Specifically, the data storage unit 209 is composed of a semiconductor memory and includes an area for storing music information CT.
[0043]
(10) Encryption / decryption unit 210
The encryption / decryption unit 210 receives the time variable key VK from the time variable key generation unit 208.
The encryption / decryption unit 210 receives the encrypted music information EncCT from the encryption / decryption unit 109, generates the music information CT by applying the decryption algorithm D2 to the encrypted music information EncCT using the time variable key VK, and generates the generated music The information CT is written in the area indicated by the access information in the data storage unit 209.
[0044]
Here, the encryption / decryption unit 210 uses DES as the decryption algorithm D2. The decryption algorithm D2 decrypts the ciphertext generated by the encryption algorithm E2.
Also, the encryption / decryption unit 210 reads the music information CT from the area indicated by the access information in the data storage unit 209, and applies the encryption algorithm E3 to the music information CT using the time-varying key VK to encrypt the music information EncCT is generated, and the generated encrypted music information EncCT is output to the encryption / decryption unit 109.
[0045]
Here, the encryption / decryption unit 210 uses DES as the encryption algorithm E3. The decryption algorithm D3 decrypts the ciphertext generated by the encryption algorithm E3.
3. Operation of authentication communication system 100
(1) Read operation
The operations of the reader / writer device 10 and the memory card 20 constituting the authentication communication system 100 will be described with reference to the flowcharts shown in FIGS.
[0046]
Here, the description will be made assuming that the reader / writer device 10 is a device that reads information stored in a memory card, such as the headphone stereo shown in FIG.
The synthesizing unit 103 reads the random number seed from the random number seed storage unit 102, reads the access information from the access information storage unit 101, synthesizes the read random number seed and the read access information, and generates randomized access information. Then, the encryption unit reads the common key from the common key storage unit 104, encrypts the randomized access information using the read common key, and generates encrypted access information R1 (step S102). The mutual authentication unit 107 calculates V2 ′ = F1 (R1) (step S103), and the random number seed update unit 106 overwrites the random number seed storage unit 102 with the generated randomized access information as a new random number seed. (Step S104).
[0047]
The encryption unit 105 outputs the generated encrypted access information R1 to the memory card 20, and the mutual authentication unit 207 of the memory card receives the encrypted access information R1 (step S105).
The mutual authentication unit 207 calculates V2 = F1 (R1) (step S106), outputs V2 to the mutual authentication unit 107 of the reader / writer device 10, and the mutual authentication unit 107 receives V2 (step S107).
[0048]
The mutual authentication unit 107 determines whether or not V2 and V2 ′ match. If they do not match (step S108), the mutual authentication unit 107 determines that the memory card 20 is an unauthorized device and stops the subsequent operation. .
If they match (Step S108), the mutual authentication unit 107 determines that the memory card 20 is a valid device, and the random number generation unit 204 of the memory card 20 reads the random number seed from the random number seed storage 202, The random number R2 is generated using the read random number seed (Step S109), the mutual authentication unit 207 calculates V1 ′ = F2 (R2) (Step S110), and the random number seed updating unit 203 generates the generated random number R2. Is overwritten in the random number seed storage unit 202 as a new random number seed (step S111). Next, the random number generation unit 204 outputs the generated random number R2 to the mutual authentication unit 107 of the reader / writer device 10, the mutual authentication unit 107 receives the random number R2 (step S112), and the mutual authentication unit 107 receives V1 = F2 (R2) is generated (step S113), and the generated V1 is output to the mutual authentication unit 207 of the memory card 20, and the mutual authentication unit 207 receives V1 (step S114).
[0049]
Next, the mutual authentication unit 207
The mutual authentication unit 207 determines whether or not V1 and V1 ′ match, and if they do not match (step S115), the reader / writer device 10 is recognized as an unauthorized device and the subsequent operation is stopped. To do.
If they match (step S115), the mutual authentication unit 207 determines that the reader / writer device 10 is a valid device, and the time-varying key generation unit 108 of the reader / writer device 10 uses R1 and R2. A time variable key VK is generated (step S121). The decryption unit 205 of the memory card 20 reads the common key UK from the common key storage unit 201, decrypts R1 using the read common key UK, generates randomized access information (step S122), and the separation unit 206. Separates the access information from the randomized access information (step S123), the time variable key generation unit 208 generates a time variable key VK using R1 and R2 (step S124), and the encryption / decryption unit 210 The music information CT is read from the area of the data storage unit 209 indicated by the access information (step S125), and the encryption / decryption unit 210 encrypts and encrypts the read music information CT using the generated time-varying key VK. Music information EncCT is generated (step S126), and the generated encrypted music information EncCT is output to the encryption / decryption unit 109 of the reader / writer device 10. (Step S127).
[0050]
The encryption / decryption unit 109 decrypts the encrypted music information EncCT using the time-varying key VK to generate the music information CT and writes it to the data storage unit 110 (step S128), and the input / output unit 111 stores the music information CT. The music information CT read out from the data storage unit 110 is converted into an audio signal and output (step S129).
(2) Write operation
Operations of the reader / writer device 10 and the memory card 20 constituting the authentication communication system 100 will be described with reference to the flowchart shown in FIG.
[0051]
Here, description will be made assuming that the reader / writer device 10 is a device for writing information to a memory card, like the personal computer shown in FIG. Since the read operation and the write operation are similar, only the difference will be described.
When steps S125 to S129 in the flowcharts of FIGS. 4 to 5 are replaced with the steps shown in FIG.
[0052]
The encryption / decryption unit 109 reads the music information CT from the data storage unit 110 (step S131), encrypts the music information CT read using the time-varying key VK, and generates encrypted music information CT (step S132). The generated encrypted music information CT is output to the encryption / decryption unit 210 of the memory card 20, and the encryption / decryption unit 210 receives the encrypted music information CT (step S133).
[0053]
The encryption / decryption unit 210 decrypts the encrypted music information EncCT using the time-varying key VK to generate music information CT (step S134), and the generated music information CT is stored in the data storage unit 209 indicated by the access information. Is written in the area (step S135).
4). Summary
As described above, since the information for accessing the confidential data storage area in which the confidential data is recorded is disturbed and transferred simultaneously with the mutual authentication, the confidentiality of the information for accessing the confidential data storage area is transferred. Can be increased.
[0054]
In addition, even if information for accessing the confidential data storage area is altered and transferred to other information due to unauthorized impersonation, mutual authentication is not established, so the confidential data storage area cannot be accessed. Can be.
In addition, since the access information for accessing the confidential data storage area is not related to the update of the random number, the periodicity of the random number can be improved.
[0055]
5. Authentication communication system 100a
An authentication communication system 100a as a modification of the authentication communication system 100 will be described.
5.1 Configuration of Authentication Communication System 100a
The authentication communication system 100a includes a reader / writer device 10a and a memory card 20, as shown in FIG.
[0056]
Since the memory card 20 is the same as the memory card 20 shown in FIG. 2, the description thereof is omitted here.
The reader / writer device 10a includes an access information storage unit 101, a random number seed storage unit 102, a synthesis unit 103, a common key storage unit 104, an encryption unit 105, a random number seed update unit 106, a mutual authentication unit 107, and a time-varying key generation unit 108. , An encryption / decryption unit 109, a data storage unit 110, an input / output unit 111, and a random number generation unit 112.
[0057]
The following description will be focused on differences from the reader / writer device 10. Since the other points are the same as those of the reader / writer device 10, the description thereof is omitted.
(1) Random number generator 112
The random number generation unit 112 reads the random number seed from the random number seed storage unit 102, generates a 64-bit long random number using the read random number seed, and outputs the generated random number to the synthesis unit 103 and the random number seed update unit 106. .
[0058]
(2) Random number seed update unit 106
The random number seed update unit 106 receives a random number from the random number generation unit 112 and overwrites the received random number in the random number seed storage unit 102 as a new random number seed.
(3) Synthesis unit 103
The synthesizer 103 receives a random number from the random number generator 112, reads the access information from the access information storage unit 101, synthesizes the received random number and the read access information, and generates randomized access information.
[0059]
5.2 Operation of authentication communication system 100a
The operation of the authentication communication system 100a will be described using the flowchart shown in FIG.
The random number generation unit 112 reads a random number seed from the random number seed storage unit 102 (step S201), generates a 64-bit long random number using the read random number seed (step S202), and the random number seed update unit 106 generates a random number. The random number is received from the unit 112, and the received random number is overwritten in the random number seed storage unit 102 as a new random number seed (step S203). Next, the synthesizing unit 103 receives a random number from the random number generating unit 112, reads the access information from the access information storage unit 101, synthesizes the received random number and the read access information, and generates randomized access information. (Step S204).
[0060]
Next, the process continues to step S102 of FIG. Since the following is the same as the operation of the authentication communication system 100, the description is omitted.
5.3 Summary
As described above, since the access information for accessing the confidential data storage area is not related to the update of the random number, the periodicity of the random number can be improved.
[0061]
6). Authentication communication system 100b
An authentication communication system 100b as a modification of the authentication communication system 100a will be described.
6.1 Configuration of authentication communication system 100b
As illustrated in FIG. 9, the authentication communication system 100b includes a reader / writer device 10b and a memory card 20b.
[0062]
(1) Configuration of reader / writer device 10b
The reader / writer device 10b includes an access information storage unit 101, a random number seed storage unit 102, a synthesis unit 103, a common key storage unit 104, an encryption unit 105, a random number seed update unit 106, a mutual authentication unit 107, and a time-varying key generation unit 108. A data storage unit 110, an input / output unit 111, a random number generation unit 112, a content key generation unit 113, an encryption unit 114, a content additional information storage unit 115, an encryption / decryption unit 116, and an encryption unit 117.
[0063]
Below, it demonstrates centering around difference with the reader / writer apparatus 10a. Since the other points are the same as those of the reader / writer device 10a, description thereof is omitted.
(A) Input / output unit 111
The input / output unit 111 accepts input of content additional information by a user operation, and writes the received content additional information in the content additional information storage unit 115.
[0064]
Here, an example of the content additional information is the number of times the content is reproduced and a usage period, and the content additional information is 8 bits long.
Further, the input / output unit 111 acquires the content data CD by a user operation, and writes the acquired content data CD in the data storage unit 110.
Here, the content data CD is music content information as an example.
[0065]
(B) Random number generator 112
The random number generation unit 112 outputs the generated random number R3 to the content key generation unit 113.
(C) Content key generation unit 113
The content key generation unit 113 reads the content additional information from the content additional information storage unit 115, receives the random number R3 from the random number generation unit 112, and uses the random number R3 and the read content additional information to obtain the content key CK according to Equation 7. Generate. Here, the content key CK is 64 bits long.

Here, + is an operator that indicates a combination of data.
[0066]
Next, the content key generation unit 113 outputs the generated content key CK to the encryption unit 114 and the encryption unit 117.
(D) Encryption unit 114
The encryption unit 114 receives the content key CK from the content key generation unit 113, reads the common key UK from the common key storage unit 104, and uses the read common key UK to apply the encryption algorithm E4 to the received content key CK. The encrypted content key EncCK is generated, and the generated encrypted content key EncCK is output to the encryption / decryption unit 116.
[0067]
Here, the encryption unit 114 uses DES as the encryption algorithm E4.
(E) Encryption / decryption unit 116
The encryption / decryption unit 116 receives the encrypted content key EncCK from the encryption unit 114, generates an Enc (EncCK) by applying the encryption algorithm E2 to the received encrypted content key EncCK using the time-varying key VK, The generated Enc (EncCK) is output to the encryption / decryption unit 211.
[0068]
Here, the encryption / decryption unit 116 uses DES as the encryption algorithm E2.
(F) Encryption unit 117
The encryption unit 117 reads the content data CD from the data storage unit 110, and applies the encryption algorithm E5 to the read content data CD using the content key CK to generate the encrypted content data EncCD. Next, the encryption unit 117 outputs the generated encrypted content data EncCD to the data storage unit 213.
[0069]
Here, the encryption unit 117 uses DES as the encryption algorithm E5.
(2) Configuration of memory card 20b
The memory card 20b includes a common key storage unit 201, a random number seed storage unit 202, a random number seed update unit 203, a random number generation unit 204, a decryption unit 205, a separation unit 206, a mutual authentication unit 207, a time varying key generation unit 208, an encryption It comprises a decryption unit 211, a key data storage unit 212, and a data storage unit 213.
[0070]
Below, it demonstrates centering on difference with the memory card 20. FIG. Since the other points are the same as those of the memory card 20, description thereof is omitted.
(A) Time-varying key generation unit 208
The time variable key generation unit 208 outputs the time variable key VK to the encryption / decryption unit 211.
(B) Encryption / decryption unit 211
The encryption / decryption unit 211 receives the time variable key VK from the time variable key generation unit 208 and receives Enc (EncCK) from the encryption / decryption unit 116.
[0071]
Next, the encryption / decryption unit 211 generates the encrypted content key EncCK by applying the decryption algorithm D2 to Enc (EncCK) using the time-varying key VK, and the generated encrypted content key EncCK is indicated by the access information Write to the area of the key data storage unit 212.
(C) Key data storage unit 212
The key data storage unit 212 includes an area for storing the encrypted content key EncCK.
[0072]
(D) Data storage unit 213
The data storage unit 213 receives the encrypted content data EncCD and stores the received encrypted content data EncCD.
6.2 Operation of authentication communication system 100b
The operation of the authentication communication system 100b is similar to the operation of the authentication communication system 100a. Here, only differences from the authentication communication system 100a will be described.
[0073]
Operation | movement of the authentication communication system 100b is shown by the flowchart which replaced step S121 after the flowchart shown in FIG. 10 among the flowcharts which show the operation | movement of the authentication communication system 100a.
The content key generation unit 113 reads the content additional information from the content additional information storage unit 115 (step S301), the random number generation unit 112 outputs the generated random number R3 to the content key generation unit 113, and the content key generation unit 113 Then, R3 is received from the random number generation unit 112, the content key CK is generated using the content additional information read as R3, and the generated content key CK is output to the encryption unit 114 and the encryption unit 117 (step S302), the encryption unit 114 receives the content key CK from the content key generation unit 113, reads the common key UK from the common key storage unit 104, and encrypts the received content key CK using the read common key UK. Encrypted content key EncCK is generated by applying algorithm E4, and the generated encryption The content key EncCK outputs to the decryption unit 116 (step S303). Next, the encryption / decryption unit 116 receives the encrypted content key EncCK, applies the encryption algorithm E2 to the received encrypted content key EncCK using the time-varying key VK, and generates Enc (EncCK) (step S304). The encryption / decryption unit 116 outputs the generated Enc (EncCK) to the encryption / decryption unit 211, the encryption / decryption unit 211 receives the Enc (EncCK) (step S305), and the encryption / decryption unit 211 receives the Enc (EncCK). The decryption algorithm D2 is applied using the variable key VK to generate the encrypted content key EncCK, and the generated encrypted content key EncCK is written in the area of the key data storage unit 212 indicated by the access information (step S306).
[0074]
The encryption unit 117 reads the content data CD from the data storage unit 110 (step S307), applies the encryption algorithm E5 to the read content data CD using the content key CK, and generates the encrypted content data EncCD (step S307). S308). The encryption unit 117 outputs the generated encrypted content data EncCD to the data storage unit 213, the data storage unit 213 receives the encrypted content data EncCD (step S309), and the data storage unit 213 receives the received encryption The content data EncCD is stored (step S310).
[0075]
6.3 Summary
As described above, in the authentication communication system 100b, a new random number generation mechanism is required to generate a content key for encrypting content data. This is shared with the random number generation mechanism used for combining access information. Can be
7). Other variations
Although the present invention has been described based on the above embodiment, it is needless to say that the present invention is not limited to the above embodiment. The following cases are also included in the present invention.
[0076]
(1) In the above embodiment, the digital work is music information, but it is compressed data represented by character data such as novels and papers, computer program software for computer games, and MP3. Data, still images such as JPEG, and moving images such as MPEG may be used.
The reader / writer device is not limited to a personal computer, and may be an output device that sells or distributes the various digital works described above. The reader / writer device is not limited to the headphone stereo, and may be a playback device that plays back a digital work. For example, it may be a computer game device, a belt-type information terminal, a dedicated device, a personal computer, or the like. The reader / writer device may have both the output device and the playback device.
[0077]
(2) In the above embodiment, the encryption algorithm and the decryption algorithm use DES, but other encryption may be used.
In the above embodiment, SHA is used, but another one-way function may be used.
The key length of the common key and the time-varying key is 56 bits, but other length keys may be used.
[0078]
(3) In the above embodiment, the combining unit 103 combines the access information and the lower 32 bits of the random number seed to generate 64-bit randomized access information. However, the present invention is not limited to this. . It may be as follows.
The combining unit 103 may generate 64-bit long randomized access information by alternately combining the 32-bit access information and the lower 32 bits of the random number seed bit by bit. Alternatively, a plurality of bits may be combined alternately. In this case, the separation unit 206 performs the reverse operation.
[0079]
(4) In the above embodiment, the random number generation unit 204 of the memory card 20 generates the random number R2 using the random number seed stored in the random number seed storage unit 202. The random number seed may be generated as the random number R2.
The time variable key generation units 108 and 208 generate time variable keys using R1 and R2, but response values may also be used. Further, the common key UK may be entangled.
[0080]
(5) In the authentication communication system 100b, the encryption unit 117 writes the encrypted content data EncCD in the data storage unit 213, but treats the encrypted content data EncCD as confidential data and puts it in the area indicated by the access information. It may be written.
The encrypted content key EncCK may be written in the data storage unit 213 without being treated as confidential data.
[0081]
Alternatively, either one of the encryption unit 114 and the encryption unit 117 may be eliminated and shared by the remaining one.
(6) The present invention may be the method described above. Further, the present invention may be a computer program that realizes these methods by a computer, or may be a digital signal composed of the computer program.
[0082]
The present invention also records the computer program or the digital signal on a computer-readable recording medium such as a floppy disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, DVD-RAM, or semiconductor memory. It is good also as what you did. Further, the present invention may be the computer program or the digital signal recorded on these recording media.
[0083]
In the present invention, the computer program or the digital signal may be transmitted via an electric communication line, a wireless or wired communication line, a network represented by the Internet, or the like.
The present invention may be a computer system including a microprocessor and a memory, wherein the memory stores the computer program, and the microprocessor operates according to the computer program.
[0084]
In addition, the program or the digital signal is recorded on the recording medium and transferred, or the program or the digital signal is transferred via the network or the like, and is executed by another independent computer system. It is good.
(4) The above embodiment and the above modifications may be combined.
[0085]
8). Industrial applicability
When copying a digital work from an output device that outputs a digital work to a semiconductor recording medium, the output device and the semiconductor recording medium can be used when authenticating each other. Also, when reading a digital work from a semiconductor recording medium on which the digital work is recorded and playing it back, it is used when each device authenticates the validity between the semiconductor recording medium and the playback device. can do.
[0086]
【The invention's effect】
In order to achieve the above object, the present invention is an authentication communication system comprising a recording medium having an area for storing digital information and an access device for reading digital information from the area or writing digital information to the area. The disturbed access information generated by disturbing the access information indicating the area is transmitted from the access device to the recording medium. And using the disturbed access information A first authentication phase in which the access device authenticates the validity of the recording medium using a challenge-response type authentication protocol, a second authentication phase in which the recording medium authenticates the validity of the access device, and the recording When both the medium and the access device are authenticated as valid, the recording medium is Used in the authentication process Access information is extracted from disturbed access information, and the access device includes a transfer phase that reads digital information from an area indicated by the extracted access information or writes digital information to an area indicated by the access information It is characterized by that.
[0087]
As a result, simultaneously with mutual authentication, information for accessing the confidential data storage area storing the confidential data is disturbed and transferred, so that the confidentiality of the information for accessing the confidential data storage area is improved. Can do.
Also, even if the information for accessing the confidential data storage area is altered and transferred to other information due to unauthorized impersonation, mutual authentication will not succeed, so the confidential data storage area will be accessed. You can make it impossible.
[Brief description of the drawings]
FIG. 1 shows an appearance of authentication communication systems 30 and 31 as a specific configuration example of an authentication communication system 100. FIG. 1A shows the appearance of an authentication communication system 30 composed of a personal computer and a memory card 20, and FIG. 1B shows an authentication communication system 31 composed of a headphone stereo, a memory card 20, and headphones. Appearance is shown.
FIG. 2 is a block diagram illustrating configurations of a reader / writer device 10 and a memory card 20 that constitute the authentication communication system 100. FIG.
FIG. 3 shows a data structure of access information, a random number seed, and randomized access information.
FIG. 4 is a flowchart showing the operation of the authentication communication system 100. In particular, it is assumed that information stored in a memory card is read. Continuing with FIG.
FIG. 5 is a flowchart showing an operation of the authentication communication system 100; Continue from FIG.
FIG. 6 is a flowchart showing the operation of the authentication communication system 100. In particular, the reader / writer device 10 is assumed to be a device that writes information to a memory card.
FIG. 7 is a block diagram showing a configuration of an authentication communication system 100a as another embodiment.
FIG. 8 is a flowchart showing operations unique to the authentication communication system 100a.
FIG. 9 is a block diagram showing a configuration of an authentication communication system 100b as another embodiment.
FIG. 10 is a flowchart showing operations unique to the authentication communication system 100b.
[Explanation of symbols]
100 Authentication communication system
10 Reader / Writer Device
101 Access information storage unit
102 random number seed storage
103 Synthesizer
104 Common key storage unit
105 Encryption section
106 Random number seed update unit
107 Mutual authentication unit
108 Time-varying key generator
109 Cryptographic decryption unit
110 Data storage unit
111 I / O section
20 Memory card
201 Common key storage unit
202 Random number seed storage unit
203 Random number seed update unit
204 Random number generator
205 Decryption unit
206 Separation part
207 Mutual authentication unit
208 Time-varying key generator
209 Data storage unit
210 Encryption / Decryption Unit

Claims (19)

An authentication communication system comprising a recording medium having an area for storing digital information, and an access device for reading digital information from the area or writing digital information to the area,
The access device is:
Transmitting disturbed access information generated by disturbing access information including address information indicating the address of the area to the recording medium, and using the disturbed access information, the recording medium by a challenge response type authentication protocol A first authentication means for authenticating the validity of
First authenticated means for authenticating the authenticity of the access device by the recording medium;
When it is authenticated that both the recording medium and the access device are valid, digital information is read from the area indicated by the address information included in the access information extracted from the disturbed access information in the recording medium, Or access means for writing digital information to an area indicated by address information included in the access information,
The recording medium is
The disturbed access information generated by disturbing the access information including the address information indicating the address of the area is received from the access device, and challenge access type authentication is performed by the access device using the received disturbed access information. A second authenticated means for authenticating the validity of the recording medium by a protocol;
Second authentication means for authenticating the authenticity of the access device;
An authentication communication system comprising: extraction means for extracting access information from the received disturbed access information when both the recording medium and the access device are authenticated as valid . The first authentication means of the access device includes:
An access information acquisition unit for acquiring access information indicating the area;
A random number acquisition unit for acquiring a random number;
A generation unit that generates the randomized access information by combining the acquired access information and the acquired random number;
An encryption unit that generates a disturbed access information by applying a cryptographic algorithm to the generated randomized access information,
The second authenticated means of the recording medium is
A response value generating unit that generates a response value from the generated disturbed access information,
The first authentication means of the access device includes:
The authentication communication system according to claim 1, further comprising: an authentication unit that authenticates the validity of the recording medium using the generated response value. The extraction means of the recording medium includes
A decoding unit for generating randomized access information by applying a decoding algorithm to the generated disturbed access information;
The authentication communication system according to claim 2, further comprising: a separating unit that separates the access information from the generated randomized access information. The access device further includes a random number seed storage unit storing a random number seed,
The authentication communication system according to claim 3, wherein the random number acquisition unit acquires a random number by reading a random number seed from a random number seed storage unit. The access device further includes:
The authentication communication system according to claim 4, further comprising: a random number seed update unit that overwrites the random number seed storage unit with the disturbed access information as a random number seed. The access device further includes a random number seed storage unit storing a random number seed,
The authentication communication system according to claim 3, wherein the random number acquisition unit acquires a random number by reading a random number seed from a random number seed storage unit and generating a random number based on the read random number seed. The access device further includes:
The authentication communication system according to claim 6, further comprising: a random number seed update unit that overwrites the generated random number as a random number type in the random number seed storage unit. A recording medium that records digital information in the area is:
Including an encryption unit that reads digital information from the area indicated by the access information, generates an encrypted digital information by applying an encryption algorithm to the read digital information,
The access means of the access device for reading digital information from the area is:
Includes a decoding unit for generating a de-di- barrel information by performing a decryption algorithm on the generated encrypted digital information,
The authentication communication system according to claim 3, wherein the decryption algorithm decrypts a ciphertext generated by the encryption algorithm. The access means of the access device for writing digital information to the area comprises
A digital information acquisition unit for acquiring digital information;
Including a cryptographic unit that generates cryptographic digital information by applying a cryptographic algorithm to the acquired digital information;
The recording medium is
Including a decryption unit that generates a digital information by applying a decryption algorithm to the generated encrypted digital information, and writes the digital information to the area indicated by the access information;
The authentication communication system according to claim 3, wherein the decryption algorithm decrypts a ciphertext generated by the encryption algorithm. The access means of the access device for writing digital information to the area comprises
A digital information acquisition unit for acquiring digital information;
A content key acquisition unit for acquiring a content key;
A first encryption unit that generates an encrypted content key by applying a first encryption algorithm to the acquired content key;
A second encryption unit that generates a double encrypted content key by applying a second encryption algorithm to the generated encrypted content key;
A third encryption unit that generates encrypted digital information by applying a second encryption algorithm to the acquired digital information using the content key;
The recording medium is
A decryption unit that generates a encrypted content key by applying a first decryption algorithm to the generated double encrypted content key, and writes the encrypted content key to the area indicated by the access information;
The authentication communication system according to claim 3, wherein the recording medium further includes an area for storing the generated encrypted digital information. An authentication communication method used in an authentication communication system including a recording medium having an area for storing digital information, and an access device that reads digital information from the area or writes digital information to the area,
Disturbed access information generated by disturbing access information including address information indicating the address of the area is transmitted from the access device to the recording medium, and the access device uses the disturbed access information to perform a challenge response. A first authentication step for authenticating the validity of the recording medium by a type authentication protocol;
A second authentication step in which the recording medium authenticates the authenticity of the access device;
When both the recording medium and the access device are authenticated as valid, the recording medium extracts access information from the disturbed access information used in the authentication process, and the access device extracts And a transfer step of reading the digital information from the area indicated by the address information included in the access information or writing the digital information to the area indicated by the address information included in the access information. Method. An information recording medium having an area for storing digital information, and an access device that reads digital information from the area or writes digital information to the area, each device between the information recording medium and the access device A computer-readable program recording medium recording an authentication communication program used in an authentication communication system for transferring digital information after authenticating authenticity,
The authentication communication program is:
Disturbed access information generated by disturbing access information including address information indicating the address of the area is transmitted from the access device to the information recording medium, and the access device uses the disturbed access information to challenge the access information. A first authentication step for authenticating the validity of the information recording medium by a response type authentication protocol;
A second authentication step in which the information recording medium authenticates the validity of the access device;
When the information recording medium and the access device are both authenticated as valid, the information recording medium extracts access information from the disturbed access information used in the authentication process, and the access device A transfer step of reading the digital information from the area indicated by the address information included in the extracted access information or writing the digital information to the area indicated by the address information included in the access information. Program recording medium. An access device that reads digital information from an area of a recording medium or writes digital information to the area,
Transmitting disturbed access information generated by disturbing access information including address information indicating the address of the area to the recording medium, and using the disturbed access information, the recording medium by a challenge response type authentication protocol An authentication means for authenticating the validity of
An authenticated means for authenticating the authenticity of the access device by the recording medium;
When it is authenticated that both the recording medium and the access device are valid, digital information is read from the area indicated by the address information included in the access information extracted from the disturbed access information in the recording medium, Or an access means for writing digital information into an area indicated by address information included in the access information. The authentication means includes
An access information acquisition unit for acquiring access information indicating the area;
A random number acquisition unit for acquiring a random number;
A generation unit that generates the randomized access information by combining the acquired access information and the acquired random number;
An encryption unit that generates a disturbed access information by applying a cryptographic algorithm to the generated randomized access information;
A transmitter for transmitting the disturbed access information,
The recording medium is
Generate a response value from the generated disturbed access information,
The access device further includes
A receiving unit for receiving the response value;
The access device according to claim 13, further comprising an authentication unit that authenticates the validity of the recording medium using the received response value. A recording medium having an area for storing digital information, the digital information being read from or written to the area by an access device,
The disturbed access information generated by disturbing the access information including the address information indicating the address of the area is received from the access device, and challenge access type authentication is performed by the access device using the received disturbed access information. An authenticated means for authenticating the validity of the recording medium by a protocol;
Authentication means for authenticating the authenticity of the access device;
An extraction means for extracting access information from the received disturbed access information when both the recording medium and the access device are authenticated as valid,
The recording apparatus, wherein the access device reads digital information from an area indicated by address information included in the access information or writes digital information to an area indicated by address information included in the access information. The extraction means includes
A decoding unit for generating randomized access information by applying a decoding algorithm to the transmitted disturbed access information;
The recording medium according to claim 15, further comprising: a separation unit that separates the access information from the generated randomized access information. Validity of each device between the recording medium and the access device, comprising a recording medium having a region for storing digital information and an access device that reads digital information from the region or writes digital information to the region An authentication communication program used in an authentication communication system for transferring digital information after performing authentication of
Disturbed access information generated by disturbing access information including address information indicating the address of the area is transmitted from the access device to the recording medium, and the access device uses the disturbed access information to perform a challenge response. A first authentication step for authenticating the validity of the recording medium by a type authentication protocol;
A second authentication step in which the recording medium authenticates the authenticity of the access device;
When both the recording medium and the access device are authenticated as valid, the recording medium extracts access information from the disturbed access information used in the authentication process, and the access device extracts And a transfer step of reading the digital information from the area indicated by the address information included in the access information or writing the digital information to the area indicated by the address information included in the access information. program. An access method for reading confidential data from the area or writing confidential data from the area in a memory device having a confidential data storage area for storing confidential data and a reader / writer that performs cryptographic communication using a common key. ,
The reader / writer device includes first common key storage means for storing a common key,
A combining step of combining the access information indicating the address for accessing the area and a random number to generate combined data;
An encryption step of encrypting the generated composite data using a common key stored in the first common key storage means to generate a first random number;
Authentication for transferring the first random number to the memory device and performing a challenge response type mutual authentication for authenticating that the counterpart device is a legitimate device with the memory device using the first random number Steps,
In the authentication step, when it is confirmed that the reader / writer device and the memory device are valid from each other, a secret is detected from the address area indicated by the access information extracted from the first random number transferred in the authentication step. An access step of reading data or writing confidential data to an address area indicated by the access information,
An access method comprising: encrypting and transferring information for accessing the area simultaneously with mutual authentication in the authentication step. A control method used in the memory device according to claim 18,
The memory device includes second common key storage means for storing a common key, and confidential data storage means for storing confidential data,
A challenge-response type mutual authentication for authenticating that the counterpart device is a legitimate device with the reader / writer device using the first random number transferred from the reader / writer device according to claim 18. An authentication step to perform;
When it is authenticated that the counterpart device is valid, the first random number transferred from the reader / writer device is decrypted using the common key stored in the second common key storage means, and the combined data A decryption step for generating
A separation step of separating access information from the combined data;
Based on the access information, store the confidential data transferred from the reader / writer device in the confidential data storage means, or read the confidential data stored in the storage data storage means based on the access information, An access step of transferring to the reader / writer device.

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