Re: Ada & Encryption / Compression

[John Howard <jhoward@sky.net>]

On Thu, 6 Mar 1997, Larry Kilgallen wrote:
> In article <osn2shxb7e.fsf@ted.vigra.com>, David L Brown
> <dbrown@ted.vigra.com> writes:
> > John Howard <jhoward@sky.net> writes:
> >> Forget about doing your own RSA encryption.
> >> 1)  RSA is patented.  You'd have to wait for the patent to expire.
> >
> > Agreed, and this might be enough to stop you.  RSA claims that you can
> > only use their implementation.

I presumed his circumstances would dictate forcing his implementation to 
be compatible with some standardized implementation offered by RSA.

> In former years, RSA did not license the patent for your own
> implementation other than with a very steep minimum fee (on
> the order of 10 million dollars, according to rumor).   That
> is now different, and prices for your own implementation are
> down to something reasonable (in my view).

I incorrectly assumed everyone must license RSA technology even if they
use their own prime numbers.  From his address and generalized question I
assumed he is a college student in Australia probably looking to do a
senior design project.  I presumed his college would not spend the money 
to acquire an RSA license even as an investment in a standardized 
implementation.  So I suggested he start simple and possibly later add a
DES variant (which presumably he would not be required to obtain a license
to implement).

[snip]
> > Don't confuse the RSA algorithm with the contest that RSA is holding
> > to crack a particular key.  They are witholding this key, not because
> > it has to do with the algorithm, but because it is part of a contest.
>
> Ah, that explains the original comment. I couldn't understand the basis.

Nope.  My comments were unrelated to any contest.  I tried to convey that
he had little chance of discovering the prime numbers used in a standard
implementation offered by RSA.  In my reasoning, as explained above, that 
left the "unlikely" event of him licensing and binding to an 
implementation authorized by RSA.  You two have since pointed out that 
event is not so unlikely for the rest of us.  But if this is to be the 
focus of a senior design project then I believe it is less likely for him
because he'll simply be interfacing to a canned implementation.  He'll 
probably need more to base a grade on.

[snip]
> Larry Kilgallen

I think the discussion has been very useful.  There is one issue left open
that should be closed though:
1)
  Is a license required (working within the U.S.) to implement (for the
  U.S. market) the RSA public key algorithm with ones own prime numbers?
  A. Always yes.
  B. Always no.
  C. Sometimes.
  D. Don't know.

2)
  Is a license required (working outside the U.S.) to implement (for the 
  U.S. market) the RSA public key algorithm with ones own prime numbers?
  A. Always yes.
  B. Always no.
  C. Sometimes.
  D. Don't know.

I don't have useful answers to these.  Luckily, I don't have to know.

-- John Howard <jhoward@sky.net>               -- Team Ada  Team OS/2 --