System and method for comparison of private values
AssigneeSap SE
InventorFlorian Kerschbaum
Life of this patent
Estimating the term…
Abstract
An embodiment includes a first system for computing a contribution to a greater-than comparison of a first private value and a second private value. The first system includes: an accessing unit configured to access the first private value; a processor unit configured to compute a first encrypted value by encrypting the first private value, compute a decrypted value by decrypting a third encrypted value, and compute a contribution to a result of the greater-than comparison by checking a relation between the decrypted value and a modulus value; and a communication unit configured to send the first encrypted value to a second system and to receive the third encrypted value.
Claims17
A second system for providing a second private value to a greater-than comparison of a first private value and the second private value, the second system comprising:
- an accessing unit configured to access the second private value;
- a communication unit configured to receive a first encrypted value computed by encrypting the first private value using a homomorphic encryption function and a public key and send a third encrypted value to the first system;
- and
- a processing unit configured to compute a second encrypted value by encrypting a randomized value using the homomorphic encryption function and the public key, the randomized value being calculated from a first random variable and the second private value and compute the third encrypted value comprising a function of a product of the first encrypted value to the power of the first random variable and of the second encrypted value, wherein the first random variable is greater than zero.
A second computer-implemented method for providing a second private value to a greater-than comparison of a first private value accessible to a first party and the second private value accessible to a second party, the method comprising:
- accessing the second private value;
- receiving a first encrypted value computed by encrypting the first private value using a homomorphic encryption function and a public key;
- computing a second encrypted value by encrypting a randomized value using the homomorphic encryption function and the public key, the randomized value being calculated from a first random variable and the second private value, wherein the first random variable is greater than zero;
- computing a third encrypted value comprising a function of a product of the first encrypted value to the power of the first random value and of the second encrypted value;
- and
- sending the third encrypted value to the first party.
Dependencies are inferred from the claim text.