How to implement AES Encrypting for ESP8266 implemented on Hardware?
Not sure if you're familiar with FPGAs, but they're used in hardware dedicated bitcoin mining boxes and contain arrays of gates and latches in which you can use C code, VHDL or schematics to implement algorithms in hardware.

https://www.design-reuse.com/articles/13981/fpga-implementation-of-aes-encryption-and-decryption.html