3 expanded posts ยท every known parent and child
Confirming suspicions that PrivaSoft is a security-through-obscurity outfit: > From: David Clavadetscher <clav@deltanet.com> > Subject: Re: Encryption algorithms used in PrivaSoft > > Dear L., > > At this time our crypto engine is patented and proprietary. If you tell me > the intent of your interest I will see what other information we can provide > to you. Call me if you like. [...]
In article <9509191929.AA15153@cs.umass.edu>, L. McCarthy <cypherpunks@toad.com> wrote: >Confirming suspicions that PrivaSoft is a security-through-obscurity outfit: > >> From: David Clavadetscher <clav@deltanet.com> >> Subject: Re: Encryption algorithms used in PrivaSoft >> >> Dear L., >> >> At this time our crypto engine is patented and proprietary. If you tell me >> the intent of your interest I will see what other information we can provide >> to you. Call me if you like. >[...] Waitasec... I was under the impression that if you patented it, you had to reveal it. That's why RC4 isn't patented (it used to be a trade secret). - Ian "IANAL yadda yadda"
David Clavadetscher of PrivaSoft writes: > At this time our crypto engine is patented and proprietary. Ian Goldberg writes: > Waitasec... I was under the impression that if you patented it, you had to > reveal it. That's why RC4 isn't patented (it used to be a trade secret). I think I have figured out now what Clavadetscher meant. According to the PrivaSoft home page, the product uses "bitmap encryption". Inspired by your mention of patents being published, I sought a relevant patent, and I believe I've found it. U.S. Patent 5,321,749 was issued to a Richard Virga of Danbury, CT in 1994. It describes a protocol for representing an arbitrary fax document as a bitmap, encrypting it, and encoding it for transmission. The user inputs a password (4-20 characters) to be used as a session key. However, no encryption algorithm is specified. (The patent suggests the familiar method of seeding a PRNG with the session key, and XORing the resulting stream with the plaintext bitmap.) Assuming this is in fact the scheme PrivaSoft uses, I posit that their "crypto engine" consists of a patented (by someone who now works for them ?) protocol wrapped around a proprietary encryption algorithm. 20 characters (the patent doesn't discuss constraints on the character set, AFAIK) looks rather short. This is one possible reason for the Commerce Dept.'s export approval. http://www.megasoft.com/privasoft/about.html discusses PrivaSoft. ftp://town.hall.org/patent/data/05321/05321749 is the text of Patent 5,321,749. -Futplex <futplex@pseudonym.com>