Re: Encryption algorithm used for the IBMi OS passwords.

I disagree that using an "unknown" encryption algorithm can be better than
using a known and widely trusted (by experts) algorithm.

You're welcome to an opinion.

First, the algorithm must be implemented in machine language (or
bytecode). By
definition, this means that the algorithm is not known.

Therefore, it is impossible to use an "unknown" algorithm.

Those two statements conflict with one another. The word "not" in the first
appears to be a typo. It sounds like you may be suggesting that if an
algorithm can be run by a machine, it can be reverse engineered by a hacker.

My point is that an unpublished (obscure) algorithm presents a significant
obstacle for hackers to overcome. You don't have to give hackers an
opportunity to reverse engineer your code.

Second, using an algorithm that

has not been vetted by math and encryption experts, is much more likely to
contain weaknesses.

I said as much in my last post. Expertise is required to come up with a
strong algorithm.

Every encryption algorithm is susceptible to brute force attack.


Depends on ones definition of "brute force attack". My definition would be
to use a program to generate and pass values to an encryption algorithm,
then compare the result to a known value. Brute force means to repeat until
you get a match.

If you don't have access to the algorithm, then you can't do that.

I essentially agree with the rest of your post about the necessity of key
based encryption, the length of the key, but I disagree with your point
about obscurity being equivalent to sticking your head in the sand.