Privacy preserving negotiation and computation

A system for the secure evaluation of a function by a group of participants, wherein each of a plurality of parties furnishes a private input to the function, and wherein, except for what may be deduced from the output of the function, the function is evaluated without any participant learning any information about the private input of any other participant, the system comprising:

• (a) exactly two servers, including:
• (i) an issuer server, said issuer server operative to preparing a description corresponding to the function and to learning a first portion of the private input;
• and
• (ii) a center server, said center server being operative to evaluating the function from said description and to learning a second portion of the private input;
• wherein
• both said first portion and said second portion are necessary to learn said private input;
• and said issuer server and said center server evaluate the function from said description by engaging in a secure two-party function evaluation, such that only said center server learns the output of the function, and such that said center server does not learn the private inputs thereto.

A method for the secure evaluation of a function by a group of participants, wherein each of a plurality of parties furnishes a private input to the function, and wherein, except for what may be deduced from the output of the function, the function is evaluated without any participant learning any information about the private input of any other participant, the method comprising:

• (a) providing at least one issuer server as a participant, said at least one issuer server being operative to preparing a description corresponding to the function;
• (b) providing at least one center server as a participant, said at least one center server being operative to evaluating the function from said description;
• (c) having each of the plurality of parties send no more than one private input to no more than one center server such that only said at least one issuer server learns a first portion of said private input, and such that only said at least one center server learns a second portion of said private input, wherein both said first portion and said second portion are necessary to learn said private input;
• and
• (d) having said at least one issuer server and said at least one center server evaluate the function from said description, such that only said at least one center server learns the output of the function, and such that said at least one center server does not learn the private inputs thereto.

A system for the secure evaluation of a function by a group of participants, wherein each of a plurality of parties furnishes a private input to the function, and wherein, except for what may be deduced from the output of the function, the function is evaluated without any participant learning any information about the private input of any other participant, the system comprising:

• (a) at least one issuer server, said at least one issuer server operative to preparing a description corresponding to the function and to learning a first portion of the private input;
• and
• (b) at least one center server, said at least one center server being operative to evaluating the function from said description and to learning a second portion of the private input;
• wherein
• both said first portion and said second portion are necessary to learn said private input;
• and said at least one issuer server and said at least one center server evaluate the function from said description by engaging in a secure two-party function evaluation, such that only said at least one center server learns the output of the function, such that said at least one center server does not learn the private inputs thereto, and such that each participant sends no more than one private input to no more than one center server.