Revisiting Variable Output Length XOR Pseudorandom Function

Pseudorandom Generators without the XOR Lemma

Impagliazzo andWigderson IW have recently shown that if there exists a decision problem solvable in time O n and having circuit complexity n for all but nitely many n then P BPP This result is a culmination of a series of works showing connections between the existence of hard predicates and the existence of good pseudorandom generators The construction of Impagliazzo andWigderson goes through ...

A Design of Cryptographic Hash Function Group with Variable Output-Length Based on SHA-1

The cryptographic hash function provides the services of information security, authentication, integrity, non-reputation in a branch of information secret. A cryptographic hash function has been developed since MD4 was proposed by Rivest. In present, U.S standard of a hash function is SHA-1 with 160 bits of output length. It is difficult to be sure of a security of a hash function with 160 bits...

Soft-input soft-output decoding of variable length codes

We present a method for utilizing soft information in decoding of variable length codes (VLCs). When compared with traditional VLC decoding, which is performed using “hard” input bits and a state machine, the soft-input VLC decoding offers improved performance in terms of packet and symbol error rates. Soft-input VLC decoding is free from the risk, encountered in hard decision VLC decoders in n...

Learning Variable Memory Length Markov Chains from Noisy Output

Secure and efficient random functions with variable-length output

Many random functions, like Hash, MAC, PRG, have been used in various network applications for different security choices, however they either are fast but insecure, or are cryptographic secure but slow. To integrate them together, in this paper we present a new family of square random functions, including SqHash, SqMAC and SqPRG, based on a specially truncated function (MSB or LSB), as well as...