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Life-Like Cellular Automata based Cryptographic Hash Function

Abstract

Cryptographic Hash Function (in short, CHF) is a useful tool for implementing one-wayencryptionthatishardtorestoretheplaintext. CHFisdefinedasafunctionfromsome set X to fixed sized string, with almost-injective property and hard to restore theoriginal input. There are many famous algorithms such as SHA-1 , commonly usedfor encrypting plain text into a string composed of alphabet and numbers, with size40. One interesting thing is, a Cellular Automata (in short, CA) has similar behavioras CHF. CA is deterministic to initial state so it’s well-defined function, and differentinitial state generates almost different output. If we take CA rule as Life-Like Cellular Automata (in short, LLCA), then it would be hard to guess initial state from generatedoutput since LLCA has non-deterministic property for inverse mapping, i.e., it’s NP problem. Therefore if we can encode given input to appropriate CA initial state andthe result, then LLCA would be suitable CHF