Re: if this is RC4

Carl Ellison says:

Assuming for the moment that alleged-RC4 came from the keyboard of Ron Rivest,

Well, from his mind -- its probably a reverse engineering job. It looks like it may be interoperable, which would imply that its real...

my question is whether to look at this as an amateur cipher from a famous cryptologist -- or as a carefully designed cipher from a professional.

Hard to tell. Its remarkably simple -- the simplest cypher I've seen in some time. It obvioously needs to be studied in detail. The possible excitement comes from its speed... .pm