Post
In discussing how I'd handle various I/O mediums in my hypothetical string-centric computer... I've mentioned the need for a cryptography a couple times! So how'd I handle this?
Many modern symmetric ciphers & hash functions use a mix of addition, bit-rotate, & XOR operations. Since knowing XOR's output still leaves the input probabilities at 50%-50%! Addition & rotation spreads this uncertainty out.
So a bare-bones "Arithmetic Core" coprocessor *with* a barrel shifter can handle these.
1/3?
For a long time I wasn't sure how I wanted to handle asymmetric ciphers, but upon seeing the need for signal analysis I decided to incorporate a grid of single-bit full-adders which (at a performance cost) can be rewired together into different maths formulas to be rapidly run over large arrays of numbers.
Caveat: No RAM or ROM.
I'd hook this up between other preprocessing circuits & our "Parsing Unit", letting it use the bit iteration & facilitating zero-cost decryption.
2/3!
On the internet we slot in TLS to provide encryption between your "client" computer & a server. TLS is split into subprotocols to negotiate how to encrypt, apply those settings, the actual data being protected, & error reporting. Our normal string-centric CPU can demux these, dispatching to the coprocessors for the crypto.
That negotiation normally simplifies asymmetric crypto challenges into symmetric crypto using a Diffie-Hellman handshake.
Our FPMA won't ever leak data through timing.
3/3!
Install bonfire.cafe
Get the full app experience
