Thanks for the answers guys. I'm going to use Vigenere cipher with random generated keys that are as long as the encoded message and this is to my knowledge unbreakable. You can send messages with sms and Twitter and not NSA or your wife would be able to crack it. The problem with this cipher is that you have to keep your keys secret though and deliver them to your friend in a safe way, basically hand to hand. RSA type cipher is good but it's not theoretically unbreakable like Vigenere is. But Vigenere cipher being unbreakable could mean that it's not legal to do ... in some countrys. Sweden is basically a US state when it comes to legal matters and I don't want a swat team kicking in my door giving me a single trip ticket to Gitmo. And I'm no criminal or anything but this is something I've been thinking about doing for almost twenty years when I first heard of the Vigenere cipher. So basically I'm doing it just because I want to but if it means trouble, like ie FSB puts Custodian in a black hole and destroys Openrepos servers I better not.