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US 7,599,491 B2Granted
Method for strengthening the implementation of ECDSA against power analysis
AssigneeCerticom Corp.
InventorRobert J. Lambert
Life of this patent
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AssigneeCerticom Corp.
InventorRobert J. Lambert
Estimating the term…
A method of inhibiting the disclosure of confidential information through power analysis attacks on processors in cryptographic systems. The method masks a cryptographic operation using a generator G. A secret value, which may be combined with the generator G to form a secret generator is generated. The secret value is divided into a plurality of parts. A random value is generated for association with the plurality of parts. Each of the plurality of parts is combined with the random value to derive a plurality of new values such that the new values when combined are equivalent to the secret value. Each of the new values is used in the cryptographic operation, thereby using the secret generator in place of the generator G in the cryptographic operation. The introduction of randomness facilitates the introduction of noise into algorithms used by cryptographic systems so as to mask the secret value and provide protection against power analysis attacks.
A computer-implemented method of masking a cryptographic operation comprising generation of a signature r, s in a public key elliptic curve cryptographic system, said operation utilizing both a long term private key d and a short term private key k, wherein r=Kx mod n with K being a public key derived from the short term private key k and a generating point G, Kx being the representation of the x coordinate of the key K and n the order of the generating point G, and wherein s=1/k (e+dr) with e being a hash of the message to be signed and d being the long term private key, said method comprising the steps of:
A cryptographic co-processor for masking a cryptographic operation comprising generation of a signature r, s in a public key elliptic curve cryptographic system, said operation utilizing both a long term private key d and a short term private key k, wherein r=Kx mod n with K being a public key derived from the short term private key k and a generating point G, Kx being the representation of the x coordinate of the key K and n being the order of the generating point G, and wherein s=1/k (e+dr) with e being a hash of the message to be signed and d being the long term private key, said cryptographic module being configured for:
Dependencies are inferred from the claim text.