EP4662829A1 - Verification of data of an authentication and key-agreement protocol process - Google Patents

Abstract

The invention relates to a verification unit (2), having: a capture unit (21) designed to capture an authentication and key-agreement protocol process, a creation unit (22) designed to derive data belonging to the authentication and key-agreement protocol process from the authentication and key-agreement protocol process using a confirmation standard (211), an authentication unit (23) designed to protect the data in terms of integrity, thereby forming integrity-protected data (232), and a provisioning unit (24) designed to provide the integrity-protected data (232). The invention also relates to a device (1) and to a method for providing integrity-protected data (232).

Description

Description

Authentication and key agreement protocol flow data authentication

Regardless of the grammatical gender of a particular term, persons with male, female or other gender identity are included.

BACKGROUND OF THE INVENTION

Field of the invention

The present invention relates to an authentication unit. The invention also relates to an associated device and an associated method for providing integrity-protected data.

Description of the state of the art

Protocols such as TLS, DTLS, QUIC or IPsec/IKEv2 can be used for cryptographically protected communication between two participants. This is first carried out by authentication and key agreement (AKA), in which the participants authenticate each other (mutual authentication) or at least authenticate one-sidedly (unilateral authentication). Furthermore, an unauthenticated key agreement is also possible, although in practice this is more relevant in special cases. During authentication and key agreement, symmetric key material (session key) is set up, which is used for cryptographic protection (encryption, integrity protection and/or authenticated encryption) of user data transmitted between participants.

In conventional cryptographic methods such as RSA or elliptic curves, authentication is usually carried out using a digital signature is used to digitally sign AKA protocol messages or AKA parameters contained therein. With conventional post-quantum (PQ) cryptographic algorithms (or generally "next generation crypto algorithms"), signature calculation is computationally intensive. Therefore, an authentication based on KEM (Key Encapsulation Mechanism) has been proposed, e.g. using KEMTLS. In both variants, however, a participant is only authenticated simply, ie with a single cryptographic procedure and a corresponding authentication credential (private key and associated digital certificate) for this procedure.

Some recommendations for the use of post-quantum cryptographic algorithms, e.g. from the Federal Office for Information Security (BSI) or the Agence nationale de la security des systemes d ' information (ANSSI), generally call for hybrid cryptographic methods in which a PQ algorithm is used together with a conventional algorithm. See BSI: Migration to Post Quantum Cryptography, Recommendations for action by the BSI, 31.05.2021, section 3.5: "Therefore, the BSI does not recommend using post-quantum cryptography alone, but only "hybrid" if possible, i.e. in combination with classical algorithms. In a hybrid key exchange, for example, the two negotiated secrets must be combined by means of a suitable key derivation function to form a session key. In high-security applications, the BSI requires the use of hybrid solutions." The combination is said to be secure as long as at least one of the cryptographic algorithms used is not broken (e.g. by a quantum computer or by an algorithmic design weakness or by an implementation problem).

An overview of PQ cryptography is provided by BSI, Quantum-safe cryptography - fundamentals, current developments and recommendations, Oct . 2021. Section 3.1.1 "Key agreement" describes a hybrid key agreement, and section 3 . 1 . 2 "Hybrid signatures and adaptation of public key infrastructures" describes a multiple signature of a message (message authentication).

Within an authentication and key agreement protocol process between two nodes, hybrid key agreement protocols involve two cryptographically different key agreements, each of which results in a session key, from which an overall session key is then formed to protect transmitted user data.

However, the design and implementation of hybrid authentication methods that combine two different cryptographic authentication algorithms is complex and cannot be easily implemented across different security protocols and different cryptographic algorithms.

The object of the invention is to provide a solution for improved authenticity protection for communication between participants.

SUMMARY OF THE INVENTION

The invention results from the features of the independent claims. Advantageous further developments and refinements are the subject of the dependent claims. Refinements, possible applications and advantages of the invention result from the following description and the drawings.

The invention relates to an authentication unit, comprising: a detection unit, designed to detect an authentication and key agreement protocol sequence, a creation unit, designed to generate data corresponding to the authentication and key agreement protocol sequence associated with the authentication and key agreement protocol flow including an attestation policy, an authentication unit configured to protect the data for integrity, thereby forming integrity-protected data, and a provisioning unit configured to provide the integrity-protected data.

In other words, the authentication unit is designed to derive an authentication of data associated with an authentication and key agreement protocol process and to provide it in an integrity-protected, in particular signed, form.

The integrity-protected data can also be referred to as certified data.

In general, the authentication and key agreement protocol flow can be understood as a communication session, a communication connection and/or a data transfer.

A session key is created through authentication and key agreement. Authentication and key agreement is known in English as "authentication and key agreement" (AKA). The created session key is designed to protect data that is exchanged in a communication protocol flow, the authentication and key agreement protocol flow. Thus, in the authentication and key agreement protocol flow (AKA flow), the previously created session key is used to protect the ongoing communication protocol, in particular the messages exchanged in the flow. The exchanged messages are an embodiment of data that is associated with the authentication and key agreement protocol flow. In particular, authentication and key agreement in one embodiment serves to establish a symmetric session key between two participants (a first and a second participant). The symmetric session key is used for cryptographic protection of user data that is transmitted between the participants (e.g. IPsec, TLS Record Layer, IEEE 802.1AE). The authentication and key agreement is authenticated by means of a first authentication credential (also referred to as a "private key") of the first participant using a first cryptographic algorithm assigned to the first authentication credential (or generally a first authentication method). Optionally (mutual authentication), the authentication and key agreement can also be authenticated by means of a second authentication credential (private key) of the second participant using a second cryptographic algorithm assigned to the second authentication credential (or generally a second authentication method).

Typically, the first cryptographic algorithm and the second cryptographic algorithm are identical, i.e. the first participant and the second participant use the same cryptographic algorithm to authenticate themselves (e.g. RSA (classic), ECO (classic), KEM (classic or PQ)).

The certification unit can also be referred to as "AKA Notarization Module", "AKA Certification System" and/or "AKA Certification Unit". The integrity-protected data can also be referred to as "AKA Certification".

The data associated with the authentication and key agreement protocol process can also be referred to as a data structure; in the sense of the invention, they are to be regarded in particular as a "still unsigned AKA authentication data structure". In particular, the feature that the data is associated with the authentication and key agreement protocol process is The term "related" to the authentication and key agreement protocol process is to be understood as meaning that the data result from an ongoing authentication and key agreement protocol or the (previous, related) authentication and key agreement. In general, the data includes, in particular, information to be authenticated relating to the authentication and key agreement protocol process.

The confirmation policy can also be referred to as an "AKA confirmation policy" or an "AKA notarization policy". In particular, it also includes several guidelines.

The authentication unit is designed to protect the data with regard to its integrity, thereby creating integrity-protected data. The authentication unit is thus designed to carry out further authentication. The further authentication creates integrity protection for the aforementioned authentication and key agreement. The aforementioned authentication and key agreement is also referred to below as the "previous authentication and key agreement".

According to the invention, a further authentication (also referred to as a confirmation and/or certification) of the preceding authentication and key agreement is therefore carried out, whereby in particular a third credential (authentication credential (private key)) is used. The third credential is different from the first authentication credential and from the possibly existing second authentication credential. Furthermore, a third cryptographic algorithm (or generally a third authentication method) is used, which is different from the first cryptographic algorithm and the second cryptographic algorithm. This further authentication according to the invention is provided in the form of the integrity-protected data and can also be referred to as AKA certification, since it previous authentication and key agreement is additionally confirmed again, although this has already been authenticated by means of the first and, if applicable, the second authentication credential and by means of the first and, if applicable, the second cryptographic algorithm.

The provision unit of the authentication unit is in particular integrated in or identical with the authentication unit.

The focus of research on post-quantum security protocols so far has been mainly on hybrid key agreement, but not on authentication. This is because the confidentiality of a communication session can also be subsequently broken if recorded protocol messages are decrypted at a later point in time.

In general, however, PQ crypto algorithms or next-generation crypto algorithms in general are not trusted to the same extent as the conventional crypto algorithms (RSA, ECC) that have been intensively studied for many years. It therefore seems sensible to use several authentication methods in combination for authentication. This can be particularly useful for particularly critical operations such as issuing a certificate via a secure communication channel (EST, SCEP) or for an onboarding process or online banking.

Hybrid key agreement protocols are known. However, these address a hybrid key agreement, but not a hybrid, multiple authentication with an authentication and key agreement (AKA, authentication and key agreement). The invention offers the advantage that it creates a protection with which a conventional, non-PQ-secure additional authentication can be practically added as an add-on system to an otherwise unchanged industrial automation system. In particular, if old devices or 3rd party components cannot be updated or cannot be updated promptly so that they themselves support PQ crypto algorithms, PQ-secure additional protection can be implemented subsequently.

This can also be understood as a PQ-secure overlay that can be retrofitted as additional protection in brownfield environments. The invention thus offers a solution for a practically realizable additional protection in order to be able to subsequently supplement existing implementations and systems for secure, authenticated communication with PQ-secure authentication. It is only sufficient for PQ-secure authentication and integrity, not for PQ-secure long-term confidentiality protection. Such protection requirements exist, for example, when transmitting control commands and measurement data in industrial control systems.

Furthermore, it can be used to implement additional hybrid protection, which is required in Europe by BS I and ANSS I. This means that if implementations only meet the current US requirements but not the European requirements, hybrid protection required for Europe can be practically added as an add-on.

Furthermore, a general, abstract construct is described in which a previous authentication and key agreement is protected with another, cryptographically different protection, thus a generic basic construct for a hybrid authentication with an authentication and key agreement. In a further development of the invention, the authentication unit is designed as a signing unit, wherein the signing unit is designed to provide the integrity-protected data in signed form.

In this embodiment, the integrity-protected data is therefore designed as signed data.

The integrity-protected data in signed form have in particular a PQ-secure digital signature or are protected by a PQ-secure KEM procedure. This means that the preceding authentication and key agreement is certified in particular using a PQ-secure digital signature procedure or using a PQ-secure KEM procedure. For the preceding authentication and key agreement, however, a classic crypto procedure is used in particular, in particular RSA signature, DSA, ECDSA. Post-quantum-secure cryptographic methods, also referred to as next-generation cryptographic methods, are in particular CRYSTALS-Dilithium, FALCON, SPHINCS+ , LMS , XMSS as well as lattice- or code-based key encapsulation mechanisms (KEM), in particular Kyber, FrodoKEM or Classic McEliece ).

Conversely, the integrity-protected data in signed form or in KEM-protected form can also have a classic, non-PQ-secure digital signature, in particular RSA signature, DSA, ECDSA, or be protected by a classic, non-PQ-secure KEM procedure. This means that the preceding authentication and key agreement is certified in particular using a classic digital signature procedure or a classic KEM procedure, e.g. using RSA encryption. For the preceding authentication and key agreement, however, a post-quantum procedure is used. In a further development of the invention, the signing unit is designed to send the data by:

- a post-quantum secure signature scheme or a post-quantum secure key encapsulation scheme or

- to protect the integrity of a classical cryptographic digital signature method, in particular an RSA signature method, DSA or ECDSA, whereby the integrity-protected data is provided in the signed form and/or in integrity-protected form.

In a further development of the invention, the data include:

- at least one message exchanged within the authentication and key agreement protocol process, also referred to as exchanged AKA messages and/or AKA protocol messages,

- a message part of a message exchanged within the authentication and key agreement protocol flow,

- a control message in an industrial automation system which was exchanged within the authentication and key agreement protocol process,

- a cryptographic hash value of a message exchanged within the authentication and key agreement protocol flow.

Preferably, the data comprises a plurality of messages and/or a plurality of message parts which were exchanged within the authentication and key agreement protocol sequence. The plurality of messages and/or a plurality of message parts can be messages and/or message parts transmitted in opposite transmission directions between the first and the second participant. Furthermore, the data can comprise a plurality of messages and/or a plurality of message parts which were exchanged within a plurality or within a multiplicity of authentication and key agreement protocol sequences between the first and the second participant. were exchanged. Furthermore, the data can comprise multiple messages and/or multiple message parts which were exchanged within a plurality or within a multitude of authentication and key agreement protocol processes between several different participants.

In a further development of the invention, the data comprise a parameter of an authentication and key agreement associated with the authentication and key agreement protocol process, in particular to be regarded as an AKA parameter contained in messages, wherein the parameter is designed as:

- an authentication credential of the authentication and key agreement associated with the authentication and key agreement protocol flow,

- information about a communication partner of the authentication and key agreement protocol process,

- an identification ID of a communication partner of the authentication and key agreement protocol process, and/or

- User data of a communication partner of the authentication and key agreement protocol process.

The parameter is associated with the authentication and key agreement protocol process. The parameter is also to be viewed as additional information that is derived and/or determined by means of an analysis of the authentication and key agreement protocol process. In particular, the parameter is designed as the aforementioned authentication credential, the aforementioned information about a communication partner, the aforementioned identification code and/or the aforementioned user data of a communication partner. The parameter facilitates a subsequent content-related evaluation and/or verification of the integrity-protected data, which can also be referred to as AKA authentication. In a further development of the invention, the authentication unit also comprises:

- a transmission unit designed to transmit the integrity-protected data.

The integrity-protected data, also referred to as AKA authentication, can be transmitted out-of-band or in-band, i.e. outside or within the cryptographically protected, authenticated communication session as part of the authentication and key agreement protocol process between a first and a second participant. With an in-band transmission, the transmission can take place within the security protocol (e.g. TLS, IPsec) itself, e.g. in a header, or it can be transmitted via a higher-level transport protocol or application protocol based on it (e.g. HTTP, CoAP, MQTT, XMPP). An in-band transmission is particularly useful if the authentication unit is provided by one of the communication partners in the authentication and key agreement protocol process. An out-of-band transmission occurs outside the cryptographically protected, authenticated communication session between the first and the second participant, which is protected by the authentication and key agreement protocol procedure. However, it can occur, for example, over the same communication network or over the same communication path.

An out-of-band transmission has the advantage that the AKA certification (e.g. a PQ-secure additional authentication) can be created, transmitted and checked independently of the actual security protocol (IPsec/IKEv2, TLS, DTLS). This makes it practical to add additional protection to unchanged, non-PQ-secure security protocols. Such additional protection alone can be sufficient especially if the integrity of the data transmission and the authenticity of the communication participants are to be protected, e.g. when transmitting tax information. in an industrial automation system. In such cases, PQ-secure encryption (and thus confidentiality) or encryption of the cryptographically protected transmitted data is often not necessary.

In a further development of the invention, the authentication unit also comprises: an encryption unit designed to provide the integrity-protected data in encrypted form.

In general, providing the integrity-protected data in encrypted form and/or using encrypted transmission (in-band or out-of-band) has the advantage that the AKA authentication made with the third credential is encrypted and thus cannot be read by attackers, which makes attacks on the third credential (e.g. side-channel attacks) more difficult. The advantage of unencrypted transmission, on the other hand, is that the AKA authentication can also be traced outside of the two participants and does not need to be additionally protected, which can save some computing power and latency on the one hand and avoids a data set that is protected with secret credentials and which may be partially guessable on the other (the latter could make attacks easier, for example, if a protocol weakness is discovered).

In a further development of the invention, the authentication and key agreement associated with the authentication and key agreement protocol sequence includes:

- a classical cryptographic algorithm, in particular a Di f f ie-Hellman-Key-Exchange or an Elliptic Curve Di f fie-Hellman-Key-Exchange,

- a classic cryptographic authentication method, in particular RSA signature, DSA, ECDSA,

- a post-quantum-secure cryptographic procedure, also referred to as a next-generation cryptographic procedure drive, in particular lattice- or code-based key encapsulation mechanisms (KEM), in particular Kyber, FrodoKEM or Classic McEliece, or

- a hybrid method (hybrid key agreement) consisting of a classical cryptographic algorithm and a post-quantum secure cryptographic method.

In a further development of the invention, the confirmation policy defines a specification under which the creation unit is designed to derive the data, wherein the specification relates to:

- a security protocol,

- an authentication and key agreement method and/or

- an authentication credential, each of the authentication and key agreements associated with the authentication and key agreement protocol flow.

The AKA Notarization Policy thus specifies for which AKA transactions an AKA notarization should be created.

In a further development of the invention, the confirmation policy defines a condition under which the creation unit is designed to derive the data, the condition comprising:

- establishing a connection,

- an update of a session key within an already established connection (update following a previous connection establishment), and/or

- a resumption of a previously existing (previous) connection, each within the framework of the authentication and key agreement protocol process. The condition is therefore also to be understood as an existing situation, a state between communication partners or a framework.

A fixed or specifiable AKA confirmation policy (AKA notarization policy) thus specifies whether only a complete AKA process that occurred during connection establishment should be recorded and confirmed, or also subsequent session key updates or even a reuse of an already established security context during a session resumption.

The invention also comprises a device having an authentication unit according to the invention.

The authentication unit can be implemented as a separate component. It can also be implemented as an additional component of a device, as in this embodiment. The device is also designed in particular to carry out the authentication and key agreement protocol process and to act as a communication partner for another device.

Such an AKA certification can thus be issued by the first participant (device) and/or by the second participant (further device), or it can be issued by a third node (proxy node, notary node, separate component) that determines the messages or message parts issued during authentication and key agreement between the first and second participants, e.g. by network monitoring, and confirms them independently of the first and second nodes.

In a further development of the invention, the device further comprises: an agreement unit, designed to carry out an authentication and key agreement, whereby a session key is created, and a communication unit configured to use the session key in the authentication and key agreement protocol process to protect a communication (in particular with another device).

The communication includes an exchange of data. The data which is exchanged within the authentication and key agreement protocol process is therefore associated with the authentication and key agreement protocol process. The data includes in particular messages or parts of messages, exchanged AKA messages, also referred to as AKA protocol messages and/or control messages in an industrial automation system.

In addition, the data associated with the authentication and key agreement protocol process are particularly designed as AKA parameters contained in messages, a cryptographic hash value of AKA messages and/or information on the communication partners involved (in particular devices, participants), in particular user data of the communication partners, an identification ID of a communication partner and/or an authentication credential used by a communication partner for the authentication and key agreement.

The invention also includes a method for providing integrity-protected data, comprising the steps of: detecting an authentication and key agreement protocol flow, deriving data from the authentication and key agreement protocol flow including an attestation policy, the data being associated with the authentication and key agreement protocol flow, protecting the data for integrity, thereby forming integrity-protected data, and providing the integrity-protected data. The authentication and key agreement protocol procedure is preceded by an authentication and key agreement to set up a symmetric session key between two participants. The symmetric session key is used to cryptographically protect user data that is transmitted between the participants as part of the authentication and key agreement protocol procedure (e.g. IPsec, TLS Record Layer, IEEE 802.1AE). The authentication and key agreement is authenticated by means of a first authentication credential (private key) of the first participant (device) using a first cryptographic algorithm associated with the first authentication credential. Optionally, in the case of mutual authentication, the (first) authentication and key agreement is additionally authenticated by means of a second authentication credential (private key) of the second participant (another device) using a second cryptographic algorithm assigned to the second authentication credential.

Typically, the first cryptographic algorithm and the second cryptographic algorithm are identical, i.e. the first participant (device) and the second participant (further device) use the same cryptographic algorithm to authenticate themselves (in particular RSA (classical), EGG (classical), KEM (classical or post-quantum)).

In a development of the invention, the method according to the invention has the further steps: carrying out an authentication and key agreement, whereby a session key is created, and communicating within the authentication and key agreement protocol sequence using the session key to protect the communication (in particular with another device). In a further development of the invention, the method according to the invention comprises the further step: checking the integrity-protected data.

The integrity-protected data (also referred to as AKA authentication) can be checked by the first and/or the second communication participant (device and/or other device). It can also be checked by a special monitoring node (separate component/unit) in order to detect if a non-PQ-secure, conventional authentication has been manipulated. If such a monitoring node is used, it can, in a variant of the invention, if necessary. can also be used advantageously as a "PQ proxy": If the second participant is a non-PQ-capable legacy device in the same network as the monitoring node, non-PQ-secure algorithms can be used for the communication session, while the PQ-secure AKA authentication of the first participant is checked by the monitoring node; based on the verification of the PQ-secure AKA authentication of the first participant, the monitoring node can then confirm to the second participant (using a non-PQ-secure procedure) that the first participant has successfully authenticated itself to the monitoring node in a PQ-secure manner and that communication can continue. This confirmation can, if necessary, be made via a purely internal interface (i.e. an interface that cannot be reached from the outside).

The AKA attestation can be checked immediately, for example to terminate the affected communication connection that has been identified as manipulated (e.g. by a participant node) or to block or restrict it (e.g. by a firewall). It is also possible to adapt the authorizations in an application protocol that is transmitted via the authenticated and cryptographic communication connection depending on whether at least one valid AKA attestation, preferably a plurality of matching AKA attestation, is available for this communication session. For example, onboarding or issuing a certificate via EST/SCEP can only take place if the additional verification of the AKA authentication has been carried out. Furthermore, authorizations for device configuration via NETCONF/YANG can be adjusted depending on the verification of an AKA authentication. For example, particularly security-critical operations such as importing or updating cryptographic keys via NETCONF/YANG to protect TSN communication can only be released if an AKA authentication for the communication session (e.g. TLS, ssh) used to protect the transmission of NETCONF/YANG is available and has been verified.

However, it is also possible to evaluate the AKA certifications retrospectively at a later point in time, e.g. after the communication connection between the first and second participants has been terminated. An alarm can then be generated, for example, in the case of invalid, implausible or inconsistent AKA certifications, or a certificate that was requested or provided via an affected authenticated communication connection can be revoked, or configuration changes to a device configuration or in a database can be rolled back, i.e. changes that have been made and logged are withdrawn.

BRIEF DESCRIPTION OF THE DRAWINGS

The special features and advantages of the invention will become apparent from the following explanations of several embodiments with reference to the schematic drawings.

Show it

Fig. 1 shows a device according to the state of the art,

Fig. 2 an authentication unit as an additional component to the device, Fig. 3 a schematic representation of integrity-protected

Data associated with the authentication and key agreement protocol process (AKA authentication), and

Fig. 4 is a schematic representation of an evaluated AKA certification.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 shows a device 1 (device 1) according to the prior art, in which an application 11 (app 11) can communicate in a protected manner using a security protocol 12 (security protocol 12) via a communication module 13 (communication protocol 13). The security protocol 12 carries out an authentication 121 and key agreement 121, in which a session key 1212 is set up to protect 122 user data of the application 11 for the transmission and wherein the device 1 authenticates itself to a communication partner using an authentication credential 1211 (auth-cred 1211).

Fig. 2 shows an embodiment of the invention for the implementation of the invention, in which an authentication unit 2 as an additional component 2 (AKA Notarization Module 2, AKA authentication system 2) to the device 1 (including the components shown in Fig. 1) forms 23 and provides 24 an authentication of an authentication and key agreement protocol sequence.

In principle, it is possible for the communication partners to authenticate themselves with a digital certificate, e.g. according to X.509, or for them to authenticate themselves using a verifiable credential or a verifiable presentation. For this purpose, a decentralized identifier of the communication partners can be stored in a decentralized transaction data (distributed ledger, blockchain, e.g. Hyperledger Indy). The affected AKA processes are captured by a capture unit 21 (AKA capture unit 21) in the communication protocol process and provided to a creation unit 22 (the AKA notarization builder component 22), which forms the still unsigned AKA authentication data structure with the AKA information to be authenticated (data associated with the authentication and key agreement protocol process).

The AKA certification data structure created is then digitally signed with a certification key 231 (Notary Cred 231) by the authentication unit 23. The digitally signed AKA certification 232 is provided by the provision unit 24. Instead of a digital signature, a KEM method can also be used to protect the certification.

The AKA authentication data structure can be verified, for example, by an AKA authentication system 2 (AKA Notarization Module 2) or by the communication partner. Depending on this, a signal or message can be provided to the communication partner so that it can adapt its functionality accordingly. Instead of a conventional digital signature, an AKA authentication 232 can generally also be designed as a verifiable credential or as a verifiable presentation. The AKA authentication unit 2 (AKA Notarization Module 2) can authenticate itself, for example, using a digital certificate, e.g. according to X.509, or using a decentralized identifier that is stored in a decentralized transaction database (distributed ledger, blockchain, e.g. Hyperledger Indy).

The AKA Notarization Module 2 can also be integrated into the device 1 (or separately as shown). In an integration, it can be arranged, for example, between the security protocol unit 12 and the communication module 13, or it can be integrated into the security protocol unit 12. The AKA certification 232 can also be transmitted "in-band", ie transmitted to the communication partner (eg as part of the User data or as part of header data of the security protocol 12 or of a communication protocol used for its transmission).

Fig. 3 shows an example of an AKA certification 232, which includes the AKA messages (AKA messages, user data that are transmitted between the participants) exchanged between the communication partners during the AKA process. In the example shown, four AKA messages 2321a, 2321b, 2321c, 2321d are shown. In general, two, three, five, six or ten AKA messages 2321a, 2321b, 2321c, 2321d can also be exchanged during an AKA process. The AKA certification 232 also includes a time stamp 2322 and a digital signature 2323 (notary signature 2323).

Instead of the actual AKA messages 2321a, 2321b, 2321c, 2321d, only one cryptographic hash value of each AKA message 2321a, 2321b, 2321c, 2321d can be included in the certification 232. It is also possible that a hash value is included that is formed via the exchanged AKA messages 2321a, 2321b, 2321c, 2321d of an AKA process.

Fig. 4 shows an example of an AKA certification 232, the content of which has been evaluated. In addition to the information on the AKA method 2324 used (e.g. RSA, DSA, ECDSA, DH, ECDH, KEM, e.g. Kyber, FrodoKEM or Classic McEliece), it includes a time stamp 2322 (or start time and end time of the AKA process), a digital signature 2323 (notary signature 2323) and information 2325a, 2325b on the communication partners involved (their identification ID and the authentication credentials Auth-Cred used by them).

Although the invention has been illustrated and described in detail by the embodiments, the invention is not limited by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the scope of the invention.

Claims

Patent claims 1. Authentication unit (2), comprising: a detection unit (21) designed to detect an authentication and key agreement protocol sequence, a creation unit (22) designed to derive data associated with the authentication and key agreement protocol sequence from the authentication and key agreement protocol sequence with the inclusion of a confirmation policy (211), an authentication unit (23) designed to protect the data for integrity, thereby forming integrity-protected data (232), wherein the authentication unit (23) is designed as a signing unit (23), wherein the signing unit (23) is designed to provide the integrity-protected data (232) in signed form, wherein the signing unit (23) is designed to: ■ a post-quantum secure signature scheme or a post-quantum secure key encapsulation scheme or ■ a classic cryptographic digital signature method for protecting integrity, whereby the integrity-protected data (232) are provided in the signed form and/or in integrity-protected form and a provision unit (24) designed to provide the integrity-protected data (232). 2. Authentication unit (2) according to claim 1, wherein the data comprises: at least one message (2321a, 2321b, 2321c, 2321d) exchanged within the authentication and key agreement protocol sequence, a message part of a message (2321a, 2321b, 2321c, 2321d) exchanged within the authentication and key agreement protocol sequence, a control message (2321a, 2321b, 2321c, 2321d) in an industrial automation system exchanged within the authentication and key agreement protocol sequence, a cryptographic hash value of a message (2321a, 2321b, 2321c, 2321d) exchanged within the Authentication and Key Agreement Protocol flow was exchanged. 3. Authentication unit (2) according to one of the preceding claims, wherein the data comprises a parameter (2325a, 2325b) of an authentication and key agreement (121) associated with the authentication and key agreement protocol sequence, wherein the parameter (2325a, 2325b) is designed as: - an authentication credential (1211) of the authentication and key agreement (121) associated with the authentication and key agreement protocol flow, - information about a communication partner of the authentication and key agreement protocol process, - an identification code of a communication partner of the authentication and key agreement protocol process, and/or - User data of a communication partner of the authentication and key agreement protocol process. 4. Authentication unit (2) according to one of the preceding claims, further comprising: a transmission unit (24) configured to transmit the integrity-protected data (232). 5. Authentication unit (2) according to one of the preceding claims, further comprising: - an encryption unit designed to provide the integrity-protected data (232) in encrypted form. 6. Authentication unit (2) according to one of the preceding claims, wherein the authentication and key agreement (121) associated with the authentication and key agreement protocol sequence: -a classical cryptographic algorithm, in particular a Diffie-Hellman key exchange or an Elliptic Curve Diffie-Hellman key exchange, - a classic cryptographic authentication method, in particular RSA signature, DSA, ECDSA, - a post-quantum secure cryptographic method, in particular lattice- or code-based key encapsulation method, in particular Kyber, FrodoKEM or Classic McEliece, or - a hybrid method consisting of a classical cryptographic algorithm and a post-quantum secure cryptographic method. 7. Certification unit (2) according to one of the preceding claims, wherein the confirmation policy (211) defines a specification under which the creation unit is designed to derive the data, where the specification refers to: - a security protocol (12) , - an authentication and key agreement method and/or - an authentication credential (1211) , each of the authentication and key agreement (121) associated with the authentication and key agreement protocol procedure. 8. Authentication unit (2) according to one of the preceding claims, wherein the confirmation policy (211) defines a condition under which the creation unit (22) is designed to derive the data, the condition comprising: - establishing a connection, - an update of a session key (1212) within an already established connection, and/or - a resumption of a previously established connection, each as part of the authentication and key agreement protocol process. 9. Device (1) comprising an authentication unit (2) according to one of the preceding claims. 10. Device (1) according to claim 9, further comprising: - an agreement unit configured to perform an authentication and key agreement 121, whereby a session key (1212) is created, and - a communication unit (13) configured to use the session key (1212) in the authentication and key agreement protocol process to protect a communication. 11. Procedure for providing integrity-protected data (232) , with the steps: - capturing an authentication and key agreement protocol flow, - deriving data from the authentication and key agreement protocol process including an attestation policy (211), the data being associated with the authentication and key agreement protocol process, - protecting the data for integrity, thereby forming integrity-protected data (232), and - providing the integrity-protected data (232) . 12. The method of claim 11, further comprising the steps of: performing an authentication and key agreement, thereby creating a session key (1212), and communicating within the authentication and key agreement protocol flow using the session key (1212) to protect the communication. 13. The method according to claim 11 or 12, with the further step: checking the integrity-protected data (232).