> > David Laight <david@l8s.co.uk> writes:
> > > - sequences where values are guaranteed not to be reproduced
> > > - random values
> > 
> > One way to do this is encrypting a counter with a 32 bit block cipher,
> > but until a few minutes ago I was unaware of any. (Now I've learned of
> > one on the cryptography mailing list.)
> 	we have needs for 16bit and 20bit, do you know of 16/20bit block cipher?

	also, a good-enough hash function which generates 16/32 bit output.
	(yes, i know it will be difficult to avoid collision....)

itojun