摘要:
This invention provides a method of computing a multiple k of a point P on an elliptic curve defined over a field, the method including the steps of representing the number k as binary vector k1, forming an ordered pair of point P1 and P2, wherein the points P1 and P2 differ at most by P, and selecting each of the bits ki in sequence, and for each of the ki, upon ki being a 0, computing a new set of points P1′, P2′ by doubling the first point P1 to generate the point P1′ and adding the points P1 and P2 to generate the point P2′ or upon ki being a 1, computing a new set of points P1′, P2′ by doubling the second point P2 to generate the point P2′ and adding the points P1 and P2 to produce the point P1′, whereby the doubles or adds are always performed in the same order for each of the bits bi, thereby minimizing a timing attack on the method. An embodiment of the invention applies to both multiplicative and additive groups.
摘要:
Improper re-use of a static Diffie-Hellman (DH) private key may leak information about the key. The leakage is prevented by a key derivation function (KDF), but standards do not agree on key derivation functions. The module for performing a DH private key operation must somehow support multiple different KDF standards. The present invention provides an intermediate approach that neither attempts to implement all possible KDF operations, nor provide unprotected access to the raw DH private key operation. Instead, the module performs parts of the KDF operation, as indicated by the application using the module. This saves the module from implementing the entire KDF for each KDF needed. Instead, the module implements only re-usable parts that are common to most KDFs. Furthermore, when new KDFs are required, the module may be able to support them if they built on the parts that the module has implemented.
摘要:
A protocol for authenticating at least one of a pair of first and second correspondents C and T in a data communication system, the method comprising the steps or storing a public key in the first correspondent C; computing a shared secret by the second correspondent T incorporating the public key C; storing the shared secret in the first correspondent C: the second correspondent T generating a challenge value a; the first correspondent C transmitting to the second correspondent T information including the stored public key C; the second correspondent T computing a test shared secret from the received public key C; the first and second correspondents computing response signals using the challenge value z and the shared secret in a one-way function fr; and the first correspondent C transmitting the computed response signal to the second correspondent T whereby the second correspondent verifies the first correspondent.
摘要:
Improper re-use of a static Diffie-Hellman (DH) private key may leak information about the key. The leakage is prevented by a key derivation function (KDF), but standards do not agree on key derivation functions. The module for performing a DH private key operation must somehow support multiple different KDF standards. The present invention provides an intermediate approach that neither attempts to implement all possible KDF operations, nor provide unprotected access to the raw DH private key operation. Instead, the module performs parts of the KDF operation, as indicated by the application using the module. This saves the module from implementing the entire KDF for each KDF needed. Instead, the module implements only re-usable parts that are common to most KDFs. Furthermore, when new KDFs are required, the module may be able to support them if they built on the parts that the module has implemented.
摘要:
A potential bias in the generation of a private key is avoided by selecting the key and comparing it against the system parameters. If a predetermined condition is attained it is accepted. If not it is rejected and a new key is generated.
摘要:
A potential bias in the generation or a private key is avoided by selecting the key and comparing it against the system parameters. If a predetermined condition is attained it is accepted. If not it is rejected and a new key is generated.
摘要:
The process of preparing higher aluminum alkyls by olefin chain growth on alkyl aluminum is improved by using on-line flow-through calorimetry to determine the aluminum concentration of a process stream, such as the aluminum alkyl feed stream, by reacting a sample portion of the process stream with a molar excess of alcohol and measuring the change in temperature. The aluminum concentration of the stream can then be adjusted as required to maintain it within a selected range.