I hope my question isn't as lazy as the title indicates. What I want to ask is how people literally integrate a PRNG with encrypting material.
I wrote a silly little script in Python a while back that took a 9 digit seed, then produced a list of 'random' numbers using a linear congruential generator. That was cool and all, but when I tried to use that with my silly internet chat program (Also in python) I failed to see what use it had. Hey, I could match letters, symbols, and numbers to the various digits as a sort of substitution cipher, but that didn't seem really secure at all. If substitution was used every-time, then no generator would be better than the other
I googled for a bit about my question, but all the results didn't seem to go into any specifics about how one would use these randomly generated numbers to encrypt anything. Anyhow, I chose to give it a shot on Cypto, and am hoping someone can either point me to an answer so this can be closed, or equally, provide an explanation.