encrypting and/or decrypting large files (AES) on a memory and storage constrained system, with “catastrophe recovery”

Question

I have a fairly generic question, so please pardon if it is a bit vague.

So, let\'s a assume a file of 1GB, that needs to be encrypted and later decrypted on a given

Answer 1

You have to work with the large file in chunks. Break a piece of the file off, encrypt it, and save it to disk; once saved, discard the unencrypted piece. Repeat. To decrypt, grab an encrypted piece, decrypt it, store the unencrypted chunk. Discard the encrypted piece. Repeat. When done decrypting the pieces, concatenate them.