Implementing Simplified DES using EEPROM
Just another SDES stuffs. I ‘ve generated Simplified DES Encryption Lookup Table by mapping both of key and plain text input becoming cipher text output. Since Plaintext was 8 bit width and key was 10 bit width, so you will have 2^18 combinantion or 262144 exactly. I put key as leftmost input and plain text as rightmost input.
If you name key as k1:k10 and Plain text as p1:p8, you can name the this process as a function f(k1:k10,p1:p8). The same way as decryption, you can name it as g(k1:k10;c1:c8). Both of encryption and decryption are just lookup table. you can implement it using EEPROM for example. It is fast, cheap and easy to implement. Have a look at both two picture below, it describes you how this process works.
Decryption Mode
Click links below to download lookup Table:
Download Encryption Lookup Table
Download Decryption Lookup Table
