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US 2011/0258455 A1Published application
Masked digital signatures
AssigneeResearch In Motion Limited
InventorsDonald B. Johnson, Scott A. Vanstone, Minghua Qu
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AssigneeResearch In Motion Limited
InventorsDonald B. Johnson, Scott A. Vanstone, Minghua Qu
Estimating the term…
The present invention relates to digital signature operations using public key schemes in a secure communications system and in particular for use with processors having limited computing power such as ‘smart cards’. This invention describes a method for creating and authenticating a digital signature comprising the steps of selecting a first session parameter k and generating a first short term public key derived from the session parameter k, computing a first signature component r derived from a first mathematical function using the short term public key, selecting a second session parameter t and computing a second signature component s derived from a second mathematical function using the second session parameter t and without using an inverse operation, computing a third signature component using the first and second session parameters and sending the signature components (s, r, c) as a masked digital signature to a receiver computer system. In the receiver computer system computing a recovered second signature component s′ by combining a third signature component with the second signature component to derive signature components (s′, r) as an unmasked digital signature. Verifying these signature components as in a usual EIGamal or ECDSA type signature verification.
A cryptographic processor at a sender in a data communication system having access to a long term private key d and a corresponding long term public key derived from said long term private key d, said processor being configured for:
A cryptographic processor at a sender in a data communication system having access to a long term private key d and a long term public key y derived from a generator g and said long term private key d, said processor being configured for:
A cryptographic processor at a verifier in a data communication system established between a sender and the verifier, said sender having generated in a secure computer system a masked signature having a first signature component r computed using a first short term public key derived from a first short term private key, a second signature component s computed using a second short term private key on said message m, a long term private key, and said first signature component r, and a third signature component c computed using said first and second short term private keys, said processor being configured for:
Dependencies are inferred from the claim text.