Lagged Fibonacci Generators (LFG) are used as a building block of key-streamgenerator in stream cipher cryptography. In this note we have used the self-shrinkingconcept in LFG and gives an upper bound 2n+m8 for the self-shrinking lagged fibonaccigenerator, where n is the number of stage and m is the word size of the LFG. Wehave also shown that the bound is attained by all the LFGs of degree n < 28, resultsupported by experiments. Keywords- Cryptography,Stream cipher,LFSR,LFG.
Moon K. Chetry, W. B. Vasantha Kandaswamy