On 24 Apr 2002 at 17:41, David Howe wrote: > > Maybe for you, I sure as hell wouldn't use it either as a key or as a > > seed into a known hashing/whiting algorithm. > its probably a better (if much slower) stream cypher than most currently in > use; I can't think of any that have larger than a 256 internal state, and > that implies a 2^256 step cycle at best; for pi to be worse, it would have > to have less than 2^256 digits. >
This is putting sillines on top of silliness. It's true that in principle that the decimal expansion of pi has an infinite number of digits, but any practical implementation of a PRNG based on pi would still have to have a finite number of accessable states. That is, to get the infinite cycle, you'd have to have some method of generating a uniform random integer 0 to infinity for the initial state, and you'd need an infinite amount of memory to store the current internal state. Neither of which is acheivable ion practice. Conversely, a PRNG whose cycle is "only" 2^256 bits long will never repeat itself during the lifetime of the device, or the lifetime of the universe for that matter. George
