Re: simple crypto solution(s)?

On Sun, Mar 18, 2018 at 05:31:48PM -0700, Lister wrote:
> I am trying to solve a little problem, but since I don't have much idea 
> about cryptography tools on linux, I would like to get some pointers 
> from this list. Also, if the problem I have develops to something big, 
> there may be a paid consulting opportunity here as well
> 
> Two entities (say A and B, non-humans) are connected through a high 
> speed, point to point, short distance (say 1m max) serial link. Both 
> entities have their own OS and file systems. I need to create a key 
> (private/public) pair and send some information (less than 256 bytes) as 
> a part of the handshake procedure between A and B (I already have a 
> custom protocol to do handshake). Also, I am not bothered about key 
> rings or publishing the public keys as the project targets a private 
> system, not connected to internet, but _CANNOT_ use symmetric keys.
> 
> My questions are:
> 
> How do I create a (moderately) strong key pair in linux for asymmetric 
> encryption?
> 
> What are the tools used?
> 
> Do these tools have APIs and source code available (this is most important)

Rule 1 of crypto: don't implement your own.

Rule 1a: don't use low-level bits from known good sources to
implement your own; go as high-level as possible.

In this case, Gnu Privacy Guard (gpg) is one of the good ways to
go. Let it do as much as possible.

-dsr-