DE102008056605A1 - Method for manipulation-secure transmission of e.g. password, from client to server via computer network, for online-banking, involves reconstructing code word, and declining execution of transaction by server - Google Patents

Abstract

The method involves representing a to-be-transmitted character string on a display of a client, in a formatted manner. A preset code word is input along with characters that are located at ends of lines of an applied line permutation, by activation of a push-button provided at other ends of the lines. Positions or names of the activated push-button are transmitted to a server. The code word is reconstructed by the server, and a transaction is received and executed by the server using an incorrect code word. The execution of the transaction is declined by the server. The permutation is printed on a foil made of plastic, paper or parchmenty material. An independent claim is also included for a computer program product for performing a method for manipulation-secure transmission of a character string from a client to a server via a computer network.

Description

The The present invention relates to a method for tamper-proof Encryption for online accounts, in particular for online bank accounts.

The Listening and Tampering Security of Online Accounts - Especially that of online bank accounts - is getting bigger by the Expecting quantity and harmfulness of malware (i.e., viruses, etc.) on the PC's of bank customers. Method, the listening to the PIN and / or a so-called man-in-the-middle Safely preventing counterfeiting attacks are technically complex and require special hardware and software on the bank customer's used PC.

Of the so-called man-in-the-middle counterfeit attack on one Transfer secured by the TAN or iTAN method proceeds as follows: Banker X wants Transfer 50 euros to Y's account. Fulfills the corresponding online form and send it off. The malware on the computer starts this transfer order before he is sent to the bank, converts him into a transfer from 5000 euros to Z, and sends this manipulated transfer order the bench. The demand of the bank to X for an iTAN for the transfer order of 5000 Euro to Z will be provided by the Malware in the reverse direction also intercepted, and it Bank client X is prompted by the bank's demand on the screen an iTAN for a transfer order of 50 Euro to Y reflected. Unknowingly X confirms with a TAN this pretended order, and the malware sends out the X entered iTAN to the bank to complete the fraudulent transfer order from 5000 Euro to Z to confirm.

The PIN / TAN, PIN / iTAN, HBCI-1, HBCI-2, and Security Token procedures not safe from man-in-the-middle attack. The encryption of the connection (eg SSL) also protects not sure, because the malware can be down even before the connection encryption turn on and the manipulations even before the connection encryption (or in the other direction: after the connection decryption) carry out.

Examples Procedures that Safely Protect Against Man-in-the-Middle Attack are those who have an ad outside of the client computer attach, such. B. HBCI-3. However, because of the physical existing cable connection between this extra hardware and the Calculator of the client still has a residual risk that malware on the computer of the client spied on the actions on the extra hardware.

A Another option is to look at the transfer details to be confirmed by the bank by SMS ("mTANs"). The disadvantage of this solution is that a cell phone is present must be and that the receipt of the SMS may take a while. In dead spots and abroad, the system does not work. Besides, it's only a matter of time until even cell phones be attacked by malware and thus this possibility also becomes uncertain.

The patents EP1472584B1 . US2005 / 0219149A1 and DE-10-2007-018802.3 , 2007 propose to ensure the security of online accounts through visual cryptography.

The patent WO-2006-020096 and the patent application DE-10-2007-029759.0 Propose to ensure the security of online accounts using Cardano cryptography.

The patent application DE-10-2007-029759.0 Proposes to ensure the security of online accounts by means of an electronic device with photo sensors and display.

The The object of the present invention is to provide a secure encryption method to provide for online accounts that submit an unmanipulable message, e.g. B. the destination account number a transfer, allowed by the client to the server.

The patent WO02 / 17556A1 suggests making authentication to online accounts more secure using printed line permutations, in the sense that in order to gain access to the account, you must have the printed line permutation and know the password, but the password is not audible is. Only authentication is secured by the method described in the patent, but no protection against counterfeiting of transactions, such as transfers, is provided.

The present invention extends and improves the invention WO02 / 17556A1 in the sense that with it transactions can be protected against counterfeiting.

To For this purpose, the line permutations are made by the account server generated at random. Then she's numbered, saved, printed and the account user on a safe as possible Way sent.

For a transaction, the account user types in the transaction data on the screen. To confirm the transaction, the account server asks for a specific line per mutation, e.g. By specifying the number of the line permutation. The user attaches or holds the line permutation to a displayed area of the screen.

This will put some letters of the entered transaction data at one end of line permutation lines, see 2 , At the other end of the line permutation is an unlabeled button that you can click with the mouse. Remark on the notation: Under letter is understood here and in the following - as usual in the computer science - every kind of distinguishable sign. In particular, the numbers 0, ..., 9 are letters in this sense.

Now a code word can be entered: if all letters of the code word At one end of at least one line, the codeword can by successively clicking the buttons at the end of a Line, at the other end of the corresponding letter stands.

If not all letters that potentially occur in a codeword can occur in the transaction or not at one End of a line, the server can be a reservoir with the rest Letters be written on the screen so that these remaining letters at the end of a line of line permutation stand. So every codeword can be entered.

Instead of on paper, the lines can also be more or less transparent films or printed on parchment. In In the case there would be more freedom, the relevant letters to arrange on the screen: they would not have to be in series anymore stand as with the kinked paper. However, slides are more expensive and more environmentally harmful.

The Lines of a line permutation should be printed in color, to differentiate them better. Further graphic Tricks are possible to make the lines for the human Make the eye more distinguishable.

The Procedure prevents the counterfeiting of the transaction by a Trojan, because if the Trojan other, d. H. fake, Transactional data to the account server sends, then gives the account user For confirmation, a codeword with the highest Probability is different than the account server expects: Therefore, then the fake transaction is not confirmed viewed and not executed.

Because the malware (on the client's computer or in the computer network) the randomly generated line connections does not know and definitely can not spy, and at the same time the letters, which describe the transaction, also used for confirmation the procedure provides effective protection against counterfeiting.

In show the drawings:

1 : Computer screen with transaction data and a card with a line permutation and codeword.

2 : Computer screen with transaction data on which the card with the line permutation is placed.

3 : Computer screen with transaction data and a map with a line permutation. The codeword is the PIN of the account user.

4 : Computer screen with transaction data on which the card with the line permutation is placed. The PIN can now be entered by mouse clicks on the corresponding unlabeled buttons.

5 : Computer screen with transaction data and a map with a line permutation. The buttons are no longer uniquely assigned to only one line. The security of the process hardly harms. (However, the name "permutation" for the line aggregation is no longer justified, it still remains with the name "line permutation")

6 : Computer screen with transaction data placed on a card with a line permutation with buttons and letters no longer assigned 1-1. Now the PIN can be entered by mouse clicks.

embodiment

The above procedure for securing a message against counterfeiting is applied to the special case of online banking. The Procedure prevents man-in-the-middle counterfeiting attack on the data of a money transfer.

Of the Bank server generates for the bank customer X a lot of Line permutations, number them, save them, print them and send them to the bank customer by mail (so similar how TAN lists are sent).

If the customer X has received the line permutations, he can start with online banking. The customer logs in (as usual with a PIN) and goes to a transfer form. He enters the transfer data in the form and sends the form to the bank server. The bank server sends the transfer data to the screen of the customer for confirmation. The account number has a special meaning here. Any digits that are not in it are shown separately on the screen. In addition, unlabeled buttons for mouse clicks are displayed. The situation is in 1 shown.

In our particular case, the account number, buttons and reservoir of the numbers not found in the account number are arranged in a row. The line permutations printed out on paper can be held on this screen on the screen with the relevant numbers and the buttons - if necessary after bending on pre-bent folds. After a possible size adjustment of the display on the screen, the lines and numbers are so that from each digit of the account number visually a line leads to a button, as well as from all the digits of the reservoir with the numbers not occurring in the account number. The situation is in 2 shown.

Now the customer can generate a codeword, which in this case consists of numbers, enter: he clicks on the buttons, which are at the end of a line of stroke permutation, at whose At the other end the respective digit of the code word is entered.

If a letter in the account number occurs several times, is the bank customer free to choose one of them and one of the corresponding ones Click buttons. The safety of the procedure that does not hurt.

The Procedure secures the transfer against counterfeiting from: when the Trojan sends other transaction data to the bank server as displayed on the screen, is highly likely by the mouse clicks of the bank customer entered a codeword that the bank server will consider it wrong. That happens with one Probably even then, if only one Digit is changed by the Trojan.

In 3 and 4 shows the situation in which the codeword is not on the paper and changes every time, but in which a fixed PIN is the codeword. This can be a second, independent of the PIN for logging PIN (Attention: if it is the same PIN as the one for logging, then there is a certain risk that the Trojan will find out the PIN when logging in by a wiretapping attack and then with the Knowing the PIN overrides the line permutation procedure).

In 5 and 6 the situation is illustrated that a button is connected over several - in this case exactly two - lines with several numbers. So you can save buttons and space. The security is still guaranteed here.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 1472584 B1 [0007]
• US 2005/0219149 A1 [0007]
• - DE 10-2007-018802 [0007]
• - WO 2006-020096 [0008]
• - DE 10-2007-029759 [0008, 0009]
• WO 02/17556 A1 [0011, 0012]

Claims (10)

Method for tamper-proof transmission a string of characters from a client through a computer network to one Server, characterized by the following steps: a) the Create, number and save graphic collections of random connection lines - from now called line permutations - through the server, b) sending the line permutations through the server to the server clients, c) the input of the character series to be transmitted by the client on the computer of the client, d) the formatted representation the set of characters to be transferred on the screen of the client, so after hanging up a line permutation on the screen some letters of the string of characters to be transmitted and possibly further letters at the end of the lines of the line permutation stand and the lines each at the other end with buttons are connected, e) the input of a predetermined code word, which consists of letters, all at ends of lines of the laid up Line permutation, by activating a button, which is at the other end of the lines, at one end of each letter of the codeword. f) The transmission of positions or name of the activated buttons to the server, G) the reconstruction of the code word entered by the user the server, h) the acceptance and, if necessary, execution of the Transaction by the server with correct codeword, i) the Rejection of the transaction execution by the server with incorrect codeword. Method according to one of the preceding claims, characterized in that the line permutations on foil made of plastic or paper or parchmentartigem material are printed. Method according to one of the preceding claims, characterized characterized in that the line permutations on pre-folded paper or gefälztem, parchment-like material are printed. Method according to one of the preceding claims, characterized characterized in that the line permutations on plastic film or paper or parchment material in black color or is printed in several different colors. Method according to one of the preceding claims, characterized characterized in that the characters of the string to be transmitted Numbers, letters and / or special characters are. Paper or parchment-like material or foil for carrying the method according to any one of claims 1 to 5, characterized characterized in that it represents line permutations and Fix on the screen with at least one tape is. Method according to one of the preceding claims, characterized characterized in that the character string itself has a password, a PIN, a TAN o. Ä. Is. Method according to one of the preceding claims, characterized in that the codeword is a password, a PIN, a TAN o. Ä. Is. Computer program product for carrying out the method according to one of claims 1 to 8, when the computer program running on a processor. Use of the method, the computer program product or of the paper or film according to any of the preceding Claims with online accounts.