摘要:
There are disclosed systems and methods for creating a self-signed implicit certificate. In one embodiment, the self-signed implicit certificate is generated and operated upon using transformations of a nature similar to the transformations used in the ECQV protocol. In such a system, a root CA or other computing device avoids having to generate an explicit self-signed certificate by instead generating a self-signed implicit certificate.
摘要:
A method is provided for obtaining a secret value for use as a key in a cryptographic operation, the secret value combining a private key, x, of one computing device with a public key, Y, of another computing device to obtain a secret value xY. The method includes obtaining a pair of scalars xo, x1 such that x=xo+x1 t where t is a scaling factor; obtaining a supplementary public key t Y; combining the scalars and the public keys to obtain a representation of the secret value xY as a linear combination of the scalars and the public keys; and utilising the secret value as a key in a cryptographic operation performed by the one computing device.
摘要:
A method of computing a cryptographic key to be shared between a pair of correspondents communicating with one another through a cryptographic system is provided, where one of the correspondents receives a certificate of the other correspondents public key information to be combined with private key information of the one correspondent to generate the key. The method comprises the steps of computing the key by combining the public key information and the private key information and including in the computation a component corresponding to verification of the certificate, such that failure of the certificate to verify results in a key at the one correspondent that is different to the key computed at the other correspondent.
摘要:
A method is disclosed for performing key agreement to establish a shared key between correspondents and for generating a digital signature. The method comprises performing one of key agreement or signature generation, and using information generated in said one of key agreement or signature generation in the other of said key agreement or said signature generation. By doing this, computations and/or bandwidth can be saved.
摘要:
A key establishment protocol includes the generation of a value of cryptographic function, typically a hash, of a session key and public information. This value is transferred between correspondents together with the information necessary to generate the session key. Provided the session key has not been compromised, the value of the cryptographic function will be the same at each of the correspondents. The value of the cryptographic function cannot be compromised or modified without access to the session key.
摘要:
A method of decrypting a message encrypted using a truncated ring cryptosystem. The method comprises selecting a window parameter T determining a plurality of windows of a predetermined size, each window being shifted by an amount less than or equal to the window parameter T. A decryption candidate is determined for each possible window. Each decryption candidate is tested to determine whether it is a valid message. The result of the decryption is chosen to be a valid message found in the previous step or if no valid message is found it is indicated that the message could not be decrypted. By this method, a constant number of decryption candidates are determined for each decryption.
摘要:
A method of communicating in a secure communication system, comprises the steps of assembling as message at a sender, then determining a security level, and including an indication of the security level in a header of the message. The message is then sent to a recipient.
摘要:
A method of communicating in a secure communication system, comprises the steps of assembling a message at a sender, then determining a security level, and including an indication of the security level in a header of the message. The message is then sent to a recipient.