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PASSWORD-AUTHENTICATED PUBLIC KEY ESTABLISHMENT
US2021167958
A method for cryptographic key provisioning includes, via a main authentication server (MAS), generating a first secret key and registering a client by performing a first portion of a first instance of a distributed threshold oblivious pseudo-random function. The first instance of the function results in the client obtaining a root secret key and the MAS obtaining a corresponding root public key. The method includes authenticating the client to the MAS by performing a first portion of a second instance of the distributed threshold oblivious pseudo-random function. The second instance of the function results in the client obtaining the root secret key. Information stored by the client, the first secret key, and a second secret key generated by a support authentication server are inputs to at least one of the first and second instances of the distributed threshold oblivious pseudo-random function.
In the context of client-server applications (e.g., online banking, internet of things (“IoT”), etc.), a client authenticates a server by means of the server's digital certificate whereas, in most of the cases, the server authenticates the client by means of a password (e.g., a password supplied by the client). In case of dispute, messages from the server, if signed with its private key, can be ascribed (e.g., attributed) without ambiguity to the author. This is not possible, however, for messages from the client.