Patent ID: 11917062
Assignee: SEAGATE TECHNOLOGY LLC
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 7:
8. A system for verifying key rotation, the system comprising:
one or more hardware processors;
an input interface executable by the one or more hardware processors and configured to input two ciphertext inputs encrypted from one or more plaintext inputs by an encryption function using different cryptographic keys, wherein the encryption function is selected from a function family having an output space of one or more convex sets, wherein for any two points in each of the convex sets, the corresponding convex set contains a whole line segment joining the two points wherein each point represents an output of a key-homomorphic pseudorandom function;
a divergence evaluator executable by the one or more hardware processors and configured to compute a divergence between the two ciphertext inputs;
a membership verifier executable by the one or more hardware processors and configured to execute a membership oracle on the two ciphertext inputs, wherein the membership oracle determines whether the two ciphertext inputs are in the same convex set and the two ciphertext inputs are determined to be members of a same convex set of the one or more convex sets if the computed divergence satisfies a separation condition; and
a validator executable by the one or more hardware processors and configured to validate that the two ciphertext inputs both correspond to a same plaintext input, responsive to determining that the two ciphertext inputs are members of the same convex set of the one or more convex sets, wherein the two ciphertext inputs do not correspond to the same plaintext input if the two ciphertext inputs are not members of the same convex set of the one or more convex sets.