General Advice

Jan Dubiec wrote:
>
>Guy Macon <http://www.guymacon.com/> wrote:
>
>> An interesting aspect of this is that we don't *really* know
>> whether what we call "RC4" is the same as the RC4 owned by RSA.
>> We do know that the two can encrypt and decrypt each other's 
>> output, and that this has been tested on millions of files.
>> For this reason, some people call the RC4 that we use 
>> "ARCFOUR" instead of "RC4."
>
>I don't think also that RC4 is a trade secret.

Nonetheless, RC4 is a trade secret, whether you think so or not.

>One of the free RC4 implementations

In other words, something that we are pretty sure is RC4, 
but we are not completely sure ss RC4, puplished by someone
who may or may not have correctly reverse-engineered RC4.

>contains following comment:

Comments by pepole who *don't* own RC4 have no validity.  
The official comment by the people who *do* own RC4 is:

"RSA Security does not hold any patents nor does it have any 
pending applications on the RC4 algorithm. However, RSA 
Security does not represent or warrant that implementations 
of the algorithm will not infringe the intellectual property 
rights of any third party. Proprietary implementations of the 
RC4 encryption algorithm are available under license from RSA 
Security Inc. For licensing information, contact: RSA Security 
Inc. 2955 Campus Drive, Suite 400, San Mateo, CA 94403-2507, 
USA, or http://www.rsasecurity.com." 

>I haven't seen this link for a long time but AFAIR Rivest 
>had invented RC4 and after that he started to work for RSA.

Are you implying that RSA does not own RC4?

Guy Macon wrote on Mon, 13 Dec 2004 04:36:09 +0000:
> 
> Jan Dubiec wrote:
[.....]
>>I don't think also that RC4 is a trade secret.
> 
> Nonetheless, RC4 is a trade secret, whether you think so or not.
If RC4 isn't a secret, it isn't also a trade secret. IMO it is
logical for an average engineer. Although I agree that lawyers (and
marketroids) use different kind of logic. ;-)

[.....]
>>One of the free RC4 implementations
> 
> In other words, something that we are pretty sure is RC4, 
> but we are not completely sure ss RC4, puplished by someone
> who may or may not have correctly reverse-engineered RC4.
Free RC4 implementations have been widely used for 10 years. IMO it
is long enough to prove that they actually implement RC4.


[.....]
>>I haven't seen this link for a long time but AFAIR Rivest
>>had invented RC4 and after that he started to work for RSA.
> 
> Are you implying that RSA does not own RC4?
I'm not. I'm only saying that R. Rivest is the inventor of RC4.
Another interesting link: http://en.wikipedia.org/wiki/RC4_%28cipher%29

Regards,
/J.D.