Do any of my mutuals understand Homomorphic encryption?
https://en.wikipedia.org/wiki/Homomorphic_encryption
Full disclosure - I have not read all of this, but it's coming up more and more in my tech circles and could use an "explain it like i'm five" approach here for initial understanding.
@chuck I can try :)
Basically with certain cryptographic systems you can perform certain operations on the crypto stream that would have a predictable effect on the plaintext stream that doesn't require you to know the key.
As a really simple example, say you had an xor based stream cipher (RC4 for a concrete example), and you have the additional requirement that everything in the cipher is alphabetic. You could toggle the case of the entire ciphertext with just XORing the whole with 0x20.
@chuck You wouldn't need the plaintext or the key to do this, and you wouldn't gain any other information.
The goal and the hunt is to identify and create crypto systems and mathematical operations you can perform on them to do useful work.
If you can create a system where you have a full algebra available to you in a Turing compete way, then you can do 'anything'.
@chuck I think this is almost certainly impossible at that level; for example you could binary search to extract data; but pure calculation, I think could be achieved with the right system; and you don't need many basic operations to then be able to do 'everything' that is closed form.