In article <barmar-3AADD2.23045801032006@comcast.dca.giganews.com>,
Barry Margolin <barmar@alum.mit.edu> wrote:

> In article <k2jNf.82228$sa3.63791@pd7tw1no>,
> roberson@hushmail.com (Walter Roberson) wrote:
>
> > In article <1141197605.709506.254390@p10g2000cwp.googlegroups .com>,
> > oneders <oneders@gmail.com> wrote:
> > >Hey guys..
> > >another question
> > >Which one is better: symmetric key algorithm or asymmetric key
> > >algorithm and why?
> >
> > That is covered in any good encryption textbook such as "Applied
> > Cryptography", and can probably easily be googled up.
> >
> > The answer, by the way, is "Neither is better, but either is better
> > than nothing."
>
> A simple answer could be: asymmetric encryption is usually more secure,
> but also significantly slower.
>
The security of an encryption algorithm depends solely on two things:
the length of the key and the strength of the resistance of the
algorithm to cryptanalysis. There is nothing in principle that makes
asymmetric algorithms more secure than symmetric algorithms. In fact,
one might argue that asymmetric algorithms are somewhat less secure
because the cryptanalyst can generate an unlimited number of
plaintext-ciphertext pairs to work with, whereas this is usually not
possible with symmetric algorithms.

Bill Stallings


/ Descriptions and errata sheets for my current books
/ and info on forthcoming books: WilliamStallings.com
/
/ Visit Computer Science Student Resource site:
/ WilliamStallings.com/StudentSupport.html