초록 ▼

A method for distributing a secret key from a key holder H to intended group members M. The method assumes that during the distribution process each party, a group member M and the key holder H, can decrypt and encrypt exchanged information such that the encrypter knows that the decrypter will be th

A method for distributing a secret key from a key holder H to intended group members M. The method assumes that during the distribution process each party, a group member M and the key holder H, can decrypt and encrypt exchanged information such that the encrypter knows that the decrypter will be the intended party. The method preferably uses a public key/private key encryption technique in which, for example, a trusted Certificate Authority in a public key infrastructure signs the certificates to provide the public keys involved in the encryption. Alternatively, the method, together with a symmetric cipher, uses a shared secret, established in an authenticated mechanism that is outside the information exchanges of the invention. Additionally, the method uses a strong mixing function that takes several items of data as input and produces a pseudo-random authentication (or digest). Inputs to the mixing function include identity stamps that are generated by each member M and key holder H. These inputs can be the identity of the stamp generator, such as a network address, port, or protocol, a timestamp, and/or a secret value that is known only to the stamp generator. The stamps include information to bind member M if generated by key holder H, and to bind key holder H if generated by member M. Consequently, the invention authenticates each communication exchange between member M and key holder H.

대표청구항 ▼

[ What is claimed is:] [1.] A method for distributing a secret key K from a key holder to a group member, comprising the steps of:the group member encrypting a code R.sub.m to form an encrypted code R.sub.me ;the group member providing said encrypted code R.sub.me and an authentication-M to said key

[ What is claimed is:] [1.] A method for distributing a secret key K from a key holder to a group member, comprising the steps of:the group member encrypting a code R.sub.m to form an encrypted code R.sub.me ;the group member providing said encrypted code R.sub.me and an authentication-M to said key holder;the key holder decrypting said encrypted code R.sub.me to acquire said code R.sub.m ;the key holder verifying said authentication-M;the key holder using said secret key K and said code R.sub.m as inputs to a reversible function to generate a code R.sub.h ;the key holder encrypting said code R.sub.h to form an encrypted code R.sub.he ;the key holder providing said code R.sub.he and an authentication-H to the group member;the group member decrypting said encrypted code R.sub.he to acquire said code R.sub.h ;the group member verifying said authentication-H; andthe group member deriving said secret key K having said code R.sub.h and said code R.sub.m as inputs to the reversible function.