DE10259269B4 - Device and method for individualized encryption and decryption as well as signature and signature verification via central components - Google Patents

Abstract

Method for the individual and transparent generation of keys in a data network with a sender and recipient, comprising the following steps: analysis of the e-mail traffic for validity of the sender address or recipient address based on an address directory, check in a key memory whether a key pair exists for the recipient address and, if not, generating an individual key pair for the recipient address, providing an interface for reading out the key memory.

Description

All previous apparatus and methods for encryption and signature of messages in computer networks are based on the distribution of personalized cryptographic keys and their use by the respective persons and services or by general, non-personalized corporate or group keys for use in a central location. In the following, the two different approaches are called end-to-end security and gateway security. Both methods use known methods of message or connection security that secure the messages or the connection using symmetric and asymmetric cryptography using various protocols. The state of the art is u. a. in [S / MIME Version 3 Message Specification, RFC 2633, June 1999], [S / MIME Version 3 Certificate Handling, RFC 2632, June 1999], [OpenPGP Message Format, RFC 2440, November 1998], [Security Architecture for the Internet Protocol, RFC 2401, November 1998] and [The TLS Protocol Verion 1.0, RFC 2446, January 1999].

A major disadvantage of end-to-end security is the high level of organizational effort that is necessary to provide each participant with the required cryptographic keys and, if necessary, tools (eg appropriate client software) and to provide them with permanent support (keys have to be added) Processes to be renewed, lost keys must be withdrawn, etc. - usually ensured by a complex "Public Key Infrastructure", PKI short).

A major disadvantage of gateway security is its low flexibility, since a static relationship between message transitions (eg, mail server) must be established to enable transparent encryption and data integrity. In addition, conventional gateway security does not allow transparent but secure communication with end-to-end security participants.

An advance in gateway security is in DE 100 08 519 C1 described. It gives a good overview of the state of the art and shows an alternative of dynamically utilizing gateway security by using a patented key exchange method for e-mail messages. Significant problems, however, remain unresolved, especially here is the restriction to domain key no transparent communication with users of end-to-end security possible.

From the WO 99/35783 is a known based on the Kerberos protocol infrastructure that provides short-term tickets, with an authentication via a login or a password.

From the US 2002/0181701 A1 a method for providing a key pair is known, wherein by a request from the client, the generated public key and further an encryption program are transmitted to the client, which then encrypts the data to be transmitted.

From the US 5,956,406 For example, there is known a method of transmitting a public key to a keyserver, wherein the public key is encrypted by the public key of the keyserver.

The invention solves this problem. The object of the invention is the possibility of having an entity participating in the message exchange appear as a full participant of an end-to-end security architecture, without establishing the organizational and administrative outlay of such an entity. It combines the benefits of gateway security with the benefits of end-to-end security. A central device acts as a gateway between the entity and the communication network (Internet) and sends and receives secure messages using standard methods (eg [S / MIME Version 3 Message Specification, RFC 2633, June 1999] or [OpenPGP Message Format , RFC 2440, November 1998]), where the keys used are full-fledged personalized PKI-compliant keys. The entity's own keys are generated on the inventions according to claims 1 to 8 and the foreign keys are determined by common search methods.

According to the invention, when establishing a communication partner who wishes to use end-to-end security, the device will provide the receiver of the message in his own entity with a public key which the sender can assign to the recipient transparently and without manual intervention and thus an encrypted one Can build communication. In this case, if there is still no key for the recipient in the own entity or if it is unusable (expired, withdrawn), after an optional validation by a validation component, a personalized, PKI-compliant key pair is generated on the device or the generation of triggered the device and the public key possibly certified by an optional certification component PKI compliant. This key is then made available to the communication partners for retrieval by common methods.

An outgoing message may be integrity-integrity-signed by the sender of its own entity by the device in which, as the message is forwarded or sent by the device, the same key as described above is used to generate or utilize a key available on the device and the identity of the sender.

The invention will be explained in more detail by means of an embodiment with reference to accompanying drawings.

Message from inside to outside: In the case of a message to be sent to the outside from within (own entity, eg company), the central component ( 2 ) based on the sender address used when sending the message through ( 1 ), determine whether a key pair already exists for this address. If there is no key pair yet, then the central component ( 2 ) the validation component ( 4 ) check the validity of the sender address (eg by comparing with an address directory ( 5 )), and if the validation is positive, generation of the key pair in ( 2 ). If the message is to be signed, this key pair can be used for a corresponding signature. If the message is to be encrypted, then via common search method z. B. at the communication partner ( 3 ) is searched for the recipient key and the message is encrypted.

Message from outside to inside: If a secure message should be sent from outside to the entity and transmitted to the inside, then the sender (communication partner, 3 ) a recipient key at the central component ( 2 ) Requests. If this recipient key does not yet exist, then the central component ( 2 ) the validation component ( 4 ) check the validity of the recipient address (eg by comparing with an address directory ( 5 )), and if the validation is positive, generation of the key pair in ( 2 ). The sender receives the generated public key and can send an encrypted message. If the message is signed, then the central component ( 2 ) also carry out the verification of the signature.

Claims (8)

Method for individual and transparent key generation in a data network with a sender and recipient, comprising the following steps: Analysis of the e-mail traffic for validity of the sender address or recipient address on the basis of an address directory, Checking in a key memory whether a key pair exists for the recipient address and, if this is not the case, generating an individual key pair for the recipient address, - Providing an interface for reading the key memory. The method of claim 1, wherein certification of the public key is performed by a certification process. Method according to claims 1, and / or 2, wherein the interface serves to make the public part of the key pair available to the outside. Method according to claims 1, 2, and / or 3, wherein a request for a public key at the interface results in the generation of a key pair or a certificate for the address of the recipient if no key pair is present in the key memory. Method according to claims 1, 2, 3, and / or 4, wherein the generation of the key pair or the certificate is made dependent on a validation process. Device, characterized by means and a device which enables the flow of a method according to the method claims 1 and 2, 3, 4, and / or 5. Device according to the preceding claim 6, comprising a processing unit, a keystore and a validation component arranged to analyze the e-mail traffic for sender addresses or recipient addresses and to check in the keystore whether a key pair for the Receiver address exists, and if not, generating an individual key pair for the recipient address, providing an interface for reading the key memory. Data carrier for a computer, characterized by the storage of a data structure which, after being loaded by a computer, enables the procedure to be carried out according to method claims 1 and 2, 3, 4, and / or 5.

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