An encryption program I have decided to share with the world. (Loosely?)Based on the one-time pad.
This encryption is theoretically impossible to crack (IRL, it's just really really hard).
You can either use the program to generate your keys (DOES NOT USE RAND), create a program to rand-generate for you, or make your own keys with random.org or by hand (read readme for details).
Accepts up to a 998 dimension input (list or string). Strings can use alphanumeric characters and some symbols.

Yeah. If you really want to encrypt something on your calculator, here's your solution. I recommend 3000+ bytes free and a TI-83+ SE or better. You'll need more RAM if you're encrypting bigger stuff though.

Enjoy.

mhmm Interesting, I should maybe give this a try to mess around

Encryption?

Well this a variation of code from my Map Converter program but it should help some, hopefully.

" ?Str1
For(A,1,dim(L1
Str1+sub("_Q",L1(A)+1,1?Str1
End
sub(Str1,2,WH?Str1
I highly doubt you can use this though just because it only deals with a list with 1's and 0's in it and uses that to create what goes into the string. Hopefully this is a good example to base something off of? If you maybe post your list to string code we could possibly help.

Well I think that is kinda how my code is set up. So without seeing the actual code I can't really help. Others might though.

Well I don't see any optimizations or ways to make that shorter or faster. Someone else might though. Sorry.

This encryption is theoretically impossible to crack (IRL, it's just really really hard).

One-time pads are impossible to break if you have a true source of randomness. (in practice: a sufficiently non-deterministic source)

Basically it does this: (Alice & Bob are the participants, Alice transmits to Bob)

[this is what I remember from reading Bruce Schneier's book 'Applied Cryptography']

Alice and Bob are both in possession of the random string R, of length n. (or both have a cryptographically secure RNG with identical seeds)
Alice wants to transmit message M (with length n) to Bob. She XORs every bit of M with the corresponding bit of R, and transmits the resulting ciphertext C to Bob. Bob, having received C, XORs every bit of C with the corresponding bit of R, thus recreating M. Then, both strings are discarded. (it's insecure to continue using them)

Eve, the eavesdropper, stands nowhere nearer to the solution, since R is completely (at least, in theory) random, and no part of R recurs systematically throughout the ciphertext. Impossible to break this scheme, but hard to implement, since the strings R must be distributed in advance to guarantee security.


EDIT: oops, I missed Galandros' post earlier... Sorry.

What would happen if you expand this a little further?
Perhaps a password program?