摘要:
A pairwise key-agreement scheme is provided for creating key agreements non-interactively between pairs of nodes disposed in a hierarchy of nodes. The scheme is non-interactive so that any two nodes can agree on a shared secret key without interaction. In addition, the scheme is identity-based so that any given node only needs to know the identity of peer nodes to compute the shared secret key. All of the nodes are arranged in a hierarchy where an intermediate node in the hierarchy can derive the secret keys for each of its children from its own secret key and the identity of the child. Accordingly, the scheme is fully resilient against compromise of any number of leaves in the hierarchy and of a threshold number of nodes in the upper levels of the hierarchy. The scheme is well-suited for environments such as mobile ad-hoc networks (MANETs), which are very dynamic, have acute bandwidth-constraints and have many nodes are vulnerable to compromise.
摘要:
A pairwise key-agreement scheme is provided for creating key agreements non-interactively between pairs of nodes disposed in a hierarchy of nodes. The scheme is non-interactive so that any two nodes can agree on a shared secret key without interaction. In addition, the scheme is identity-based so that any given node only needs to know the identity of peer nodes to compute the shared secret key. All of the nodes are arranged in a hierarchy where an intermediate node in the hierarchy can derive the secret keys for each of its children from its own secret key and the identity of the child. Accordingly, the scheme is fully resilient against compromise of any number of leaves in the hierarchy and of a threshold number of nodes in the upper levels of the hierarchy. The scheme is well-suited for environments such as mobile ad-hoc networks (MANETs), which are very dynamic, have acute bandwidth-constraints and have many nodes are vulnerable to compromise.
摘要:
A method of performing biometric authentication of a person's identity including a biometric template prior to storing it in a biometric database. The encryption algorithm encrypts the biometric template using a pass-phrase, known only to the individual, to generate the cryptographic key used to store and retrieve the biometric template. When an individual wishes to access a secured resource, he must be authenticated by providing an identifier which is used to retrieve the appropriate record. He must also provide the correct password to allow the system to decrypt the model.
摘要:
This invention is a method and apparatus which provide a solution to the problem of constructing efficient and secure digital signature schemes. It presents a signature scheme that can be proven to be existentially unforgeable under a chosen message attack, assuming a variant of the RSA conjecture. This scheme is not based on “signature trees”, but instead it uses a “hash-and-sign” paradigm, while maintaining provable security. The security proof is based on well-defined and reasonable assumptions made on the cryptographic hash function in use. In particular, it does not model this function as a random oracle. The signature scheme which is described in this invention is efficient. Further, it is “stateless”, in the sense that the signer does not need to keep any state, other than the secret key, for the purpose of generating signatures.
摘要:
The present invention provides a technique, system, and computer program for a symmetric key block cipher. Variable block sizes and key sizes are supported, as well as a variable number of rounds. The cipher uses multiple stages of processing, where the stages have different structures and different subround functions, to provide excellent resistance to both linear and differential attacks. Feistel Type-3 networks are used, with different networks during different stages. The number of rounds may vary among stages. Subkeys are used in some, but not all, stages. The variable-length keys can be precomputed. A novel manner of using multiplication in a cipher is defined.
摘要:
A method and apparatus for an advanced byte-oriented symmetric key cipher for encryption and decryption, using a block cipher algorithm. Different block sizes and key sizes are supported, and a different sub-key is used in each round. Encryption is computed using a variable number of rounds of mixing, permutation, and key-dependent substitution. Decryption uses a variable number of rounds of key-dependent inverse substitution, inverse permutation, and inverse mixing. The variable length sub-keys are data-independent, and can be precomputed.
摘要:
A method and apparatus for an advanced symmetric key cipher for encryption and decryption, using a block cipher algorithm. Different block sizes and key sizes are supported, and a different sub-key is used in each round. Encryption is computed using a variable number of rounds of mixing, permutation, and key-dependent substitution. Decryption uses a variable number of rounds of key-dependent inverse substitution, inverse permutation and inverse mixing. The variable length sub-keys are data-independent, and can be precomputed.
摘要:
The present invention provides a technique, system, and computer program for a symmetric key block cipher. This cipher uses multiple stages with a modified Type-3 Feistel network, and a modified Unbalanced Type-1 Feistel network in an expansion box forward function. The cipher allows the block size, key size, number of rounds of expansion, and number of stages of ciphering to vary. The modified Type-3 cipher modifies the word used as input to the expansion box in certain rounds, to speed the diffusion properties of the ciphering. The modified Type-3 and Type-1 ciphers are interleaved, and provide excellent resistance to both linear and differential attacks. The variable-length subkeys and the S-box can be precomputed. A minimal amount of computer storage is required to implement this cipher, which can be implemented equally well in hardware or software (or some combination thereof).
摘要:
The present invention provides a technique, system, and computer program for a symmetric key block cipher. Variable block sizes and key sizes are supported, as well as a variable number of rounds. The cipher uses multiple stages of processing, where the stages have different structures and different subround functions, to provide excellent resistance to both linear and differential attacks. Feistel Type-1 and Type-3 are both used, each during different stages. The number of rounds may vary among stages. Subkeys are used in some, but not all, stages. The variable-length keys can be precomputed. A novel manner of using data-dependent rotation in a cipher is defined.
摘要:
An access control system and method includes a risk index module which computes a risk index for a dimension contributing to risk. A boundary range defined for a parameter representing each risk index such that the parameter above the range is unacceptable, below the range is acceptable and in the range is acceptable with mitigation measures. A mitigation module determines the mitigation measures which reduce the parameter within the range by mapping the effectiveness of performing the mitigation measures to determine a residual risk after a mitigation measure has been implemented.