ENCRYPTION AND VERIFICATION USING PARTIAL PUBLIC KEY

摘要

A method and device for using a partial public key in a cryptosystem. The cryptosystem may be based on a group, such as an elliptic curve over a finite field. The device includes a first memory for storing system parameters of the cryptosystem and a second memory for storing a portion of a public key of the cryptosystem. The device receives the complete public key, or the remainder of the public key, via communication with another device. The received portion of the public key is used to form a validated public key. A processor of the device uses the validated public key for encrypting messages and/or verifying signatures. The size of the second memory is reduced since only part of the public key is stored.