I built AES and DES in Excel almost about a decade ago. Note that these are combinational circuits, not sequential - so no feedback or clock are required. https

I built AES and DES in Excel almost about a decade ago. Note that these are combinational circuits, not sequential - so no feedback or clock are required. https://www.nayuki.io/page/aes-cipher-internals-in-excel https://www.nayuki.io/page/aes-cipher-internals-in-excel , https://www.nayuki.io/page/des-cipher-internals-in-excel https://www.nayuki.io/page/des-cipher-internals-in-excel