Method and apparatus for distributing shares of a password for use in multi-server password authentication

摘要

A method for distributing a password amongst a plurality of servers for subsequent use in a provably secure multi-server threshold password authentication process. A client, having a password to be authenticated by a plurality of servers, generates an encryption of a function of the password. Then, this encryption is provided to each of the servers for use in subsequent password authentication. In accordance with one illustrative embodiment of the invention, the encryption is of an ElGamal ciphertext of the function g^(π_C)−1, where π_C is password and g is the generator used to generate the cryptographic keys used for communication between the client and the plurality of servers.