Method and system for establishing secure communications using composite key cryptography

摘要

A method is disclosed for establishing a secure communication session using composite key cryptography. The method comprises generating a first plurality of secret keys all of which are known only to a first communicating party and each one of which is shared with exactly one of a plurality of stewards, and generating a second plurality of secret keys all of which are known only to a second communicating party and each one of which is shared with exactly one of the plurality of stewards. The first and second communicating parties each send information to the other through different stewards, each communication leg being encrypted using a secret key known only to the respective communicating party and steward. These communications are usable to distribute cryptographic seeds to the communicating parties for use in generating a temporary session key that can be used to encrypt direct communications between the parties.

主权项

1. A method for secure data communication between a first communicating party and a second communicating party, the method comprising:
generating, by a processing machine comprising a processor, a first digital composite key comprising a first plurality of secret keys, each of the first plurality of secret keys being known only to the first communicating party and exactly one of a plurality of trusted parties and each of the plurality of trusted parties knowing exactly one of the first plurality of secret keys; generating a second digital composite key comprising a second plurality of secret keys, each of the second plurality of secret keys being known only to the second communicating party and exactly one of the plurality of trusted parties and each of the plurality of trusted parties knowing exactly one of the second plurality of secret keys; selecting a first trusted party from the plurality of trusted parties; encrypting first information by the first communicating party using the secret key known only to the first communicating party and the first trusted party; sending the encrypted first information by the first communicating party to the first trusted party; encrypting second information by the first trusted party using the secret key known only to the second communicating party and the first trusted party to provide first encrypted second information; sending the first encrypted second information by the first trusted party to the second communicating party; and decrypting the first encrypted second information by the second communicating party.