Re: Truncated multiplication (is it secure???)

"Amitabh" <amitabh123@xxxxxxxxx> (07-03-26 12:03:15):

I'm always looking for clear definitions. Given an operation that
is commutative, associative and (as I know now) not idempotent, with
operands and result statistically unrelated, can't it be used to
create a secure key exchange right away?

It would, if it also satisfies another property - infeasible to
invert, given one of the inputs.
Generally such a function is called as "Strong Associative One-Way
Function". Let this function be f: A x A -> A (for some sets A). The
"strong"-ness implies that given f(a, b), and a, it is infeasible to
compute b.

Of course, yes. I've just forgotten to mention that, but I've done so
in an earlier post anyway.


Regards,
Ertugrul Söylemez.


--
From the fact that this CGI program has been written in Haskell, it
follows naturally that this CGI program is perfectly secure.
.

Relevant Pages

  • Re: Truncated multiplication (is it secure???)
    ... create a secure key exchange right away? ... but it has shown to be insecure in that particular case. ... From the fact that this CGI program has been written in Haskell, ...
    (sci.crypt)
  • Re: Truncated multiplication (is it secure???)
    ... clever way) can be reduced on the hardness of the inversion of the ... If this wouldn't be the case, the inverting the function ... a secure key exchange right away? ... From the fact that this CGI program has been written in Haskell, ...
    (sci.crypt)
  • Re: Truncated multiplication (is it secure???)
    ... operands and result statistically unrelated, can't it be used to create ... a secure key exchange right away? ... Groups, you obtain a "Group with Infeasible Inversion", where it is ...
    (sci.crypt)
Quantcast