Abstract:
The invention discloses a cryptographic system and consisting of three methods: a cryptographic Vernam stream cipher that permits software programs on separate computers to encrypt and decrypt information; a cryptographic keyed one-way hash that ensures the integrity and authenticity of a message; a non-cyclic pseudo-random number generator that permits a software program inside a computer to create large amounts of pseudo-random bits at high data rates.
Abstract:
An efficient and practical method for dynamically maintaining an authenticated dictionary uses a skip list data structure and communicative hash functions to provide a dictionary database (201) that stores information objects so that any individual object can be authenticated as belonging or not belonging to the dictionary. The authentication consists of a short sequence of vales that begin with an element and a sequence of values that, when hashed in order using a cryptographic associative hash function, create the same value as the hashed digest of the entire dictionary. Rather than hashing up a dynamic 2-3 tree, hashes are created in a skip list. Validation of the result of the authenticating step is provided if the hash of the short sequence matches a signed hash of the entire skip list.
Abstract:
Daniel (alternatively written as DNL) is a cryptographic paradigm, featuring ease of matching many plaintexts of choice to any given cipher (the deniability property). Consequently, the cipher itself cannot betray the specific plaintext that generated it, as it is "lost" in the large list of candidate plaintexts, all of which are decryption-generated from the the ciphertext.
Abstract:
A comcryptor (100) works together with a compressor set (105) and a permutation set (110). The comcryptor (100) performs simulataneous compression and encryption of input source data (115) based on the input key (120). The output of the comcryptor (100) is compressed and encrypted, that is to say comcrypted, data (125). The compressor set (105) includes multiple compression algorithms for use by the comcryptor (100). Typically at least two compression algorithms are available in the compressor set (105), but any number may be present. The larger the number of compression algorithms are available in the compressor set (105), but any number may be present. The larger the number of compression algorithms in the compressor (105) is, the greater the lever of security is.
Abstract:
Disclosed is a multi-purpose transaction card system comprising an issuer (101), one or more cards (102), one or more terminals (103), and optionally one or more acquirers (104), communicating using a variety of cryptographic confidentiality and authentication methods. Cards authenticate messages using public-key based cryptographic without themselves performing the extensive computations usually associated with such cryptography. Integrity of complex transaction sequences and plural card storage updates are maintained, even under intentionally generated interruptions and/or modifications of data transmitted between card and terminal. Cards do not reveal any information to the terminal which is not directly necessary for the transaction or any information to which the terminal should not have access, through externally measureable aspects of its behaviour. Transaction types supported include those suitable for off-line credit cards, in which the "open to buy" is maintained on the card.
Abstract:
The present invention describes new digital signature schemes that are provably secure against any adaptive chosen-message attack. The scheme, which is based on selection of a hash function from a space of such functions, has a very short public key, fast signing, a reasonable signature length and high security. Several algorithmic techniques are provided for enhancing the efficiency of the signature scheme in terms of time and memory.
Abstract:
The present invention provides a public key cryptosystem which comprises an encryption device, said device having means for encrypting information including a feed-back loop which evaluates a one-way or a one-way trap door function incorporating modular exponentiation with a small positive exponent and thereby processes successively the blocks into which the information has been divided, to encrypt the information; and a compatible decryption device. The encryption and decryption devices of the present invention provide an outstandingly high rate of encryption and decryption without impairing the level of security associated with public key cryptosystems.
Abstract:
A method of encrypting data using a sequence of two or more data compression algorithms wherein the output of one algorithm is the input of the next algorithm if any and one or more algorithms each produce output embodying one or more codec dictionaries and one algorithm produces output not embodying a codec dictionary which algorithm uses an external pre-existing codec dictionary as its source of references. Further where if more than one algorithm emits output embodying a codec dictionary, one such algorithm operates on bytes of input and another operates on bits of input.
Abstract:
A method of improving the efficiency of an encryption/decryption process implementing the NIST FIPS 197 standard which includes a substitution box (S-box) and an inverse substitution (inverse S-box), comprises concatenating the S-box and inverse S-box to form a combined lookup table, and folding the concatenated table to generate a folded lookup table. The folded lookup table may be indexed for an encryption operation and for a decryption operation using a signal indicative of whether encryption or decryption is used.
Abstract translation:一种提高实施NIST FIPS 197标准的加密/解密过程的效率的方法,其包括替换盒(S盒)和反向替代(反S盒),包括将S盒和反S盒 以形成组合的查找表,并折叠连接的表以生成折叠查找表。 折叠查找表可以被索引用于加密操作,并且对于使用指示是否使用加密或解密的信号进行解密操作。