Hello, For Pseudo Random Numbers Generator based on linear recurrences, using SHA-1 over the PRNG's output appears to be the mostly common approach to make the output cryptographically secure. Are there any approaches that is not as computationally intensive as passing it over SHA-1/other block ciphers such that the output is cryptographically secure. Cryptographically secure as in the output sequence cannot be predicted to the left or right, given a substantially long subsequence of the output. Thank you, Sarad. ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping