When developing programs or websites, it is very convenient to use relational databases, which contain powerful and tools that allow work with data flexibly get the necessary information in a matter of milliseconds. A database consists tables records these tables, each table must have primary key, particular, can be number BIGINT type, unique index record table, allows fetch operation maximum s...

This paper advocates a new hash function family based on the HAIFA framework, inheriting built-in randomized hashing and higher security guarantees than the Merkle-Damg̊ard construction against generic attacks. The family has as its special design features: a nested feedforward mechanism and an internal wide-pipe construction within the compression function. As examples, we give two proposed ins...

Cohen, G.D. and G. Zemor, Write-isolated memories (WIMs), Discrete Mathematics 114 (1993) 105-113. A write-isolated memory (WIM) is a binary storage medium on which no change of two consecutive positions is allowed when updating the information stored. We prove that the optimal rate for writing on a WIM is log,(l +$);‘2 =0.69. We give asymptotic constructions achieving 0.6.