At work, I was asked to create ultra-secure connection over lan between two computers. It will be some kind of messager. I have a bunch of same random data in them(near 100mb). Also I can start a server with same data. I will not have access to clients, so I will not be able to update the random data on them.

Can I use XOR?

  • $\begingroup$ Welcome to crypto.stackexchange - Unfortunately this question is way too broad; We require questions that can precisely be answered, rather than discussed. Have you considered TLS? $\endgroup$ – Ella Rose Mar 16 '19 at 13:54
  • $\begingroup$ @EllaRose, Thanks. I'm just trying to make question more relevant (and follow the rules). $\endgroup$ – north32 Mar 16 '19 at 14:03
  • $\begingroup$ Pretty much anything you do with a computer will involve XOR, including using TLS. Could you be more specific about what your security criteria are? If you're thinking of using a one-time pad—which TLS does internally for most common cipher suites, generated by a stream cipher much faster and more reliably and safer than your 100 MB of random data likely are, and not limited to transmitting 100 MB on the network—note that a mere one-time pad will do nothing to prevent forgery, which TLS does prevent as long as the endpoints can authenticate each other, e.g. with certificates. $\endgroup$ – Squeamish Ossifrage Mar 16 '19 at 14:06
  • $\begingroup$ @SqueamishOssifrage I was asked to make algorithm super simple. Something like handwrite realisation. So if I will not find the way, I'll use your and Ella Rose advice. Thanks! $\endgroup$ – north32 Mar 16 '19 at 14:08
  • $\begingroup$ What is handwrite realization? If you mean you're going to do this by hand…why are there computers involved? To make this question answerable, you need to be more specific about what your goals and engineering constraints are; qualifiers like ‘ultra-secure’ don't mean anything. $\endgroup$ – Squeamish Ossifrage Mar 16 '19 at 14:15