Multiplexer Decoder Priority Encoder Image Source: https://www.wambooli.com/blog/?p=7403 Standard Keypad. Num Lock returns numerical value. Num Unlock returns navigation value. E represents the current being off / on = 0/1. Significant for High /Low. Assignment to create a Combinational Logic Circuit function. The user will one key at a time enter a two- digit password. When the key is depressed a voltage on its wire is sent. The wire represents the origin of a represented numerical value. Interpret the voltage signal as a binary 0/1 and convert to binary value. The difference between hashing and encryption, in short, encryption is a two-way function that includes encryption and decryption while hashing is a one-way function that changes a plain text to a unique value that is irreversible. We are building an encryption / decryption routine. A register will have stored in it the encrypted value to grant access. The encrypted value would be retrieved and encoded to determine authorization granted 0=No 1=Yes. There should be a logic function to receive the two individual values, e.g. 47, and calculate it as forty-seven then use decoding (encrypting) circuit to transform value. Place value in memory register. enter two individual values calculate as before, compare to encoded value from register to determine authorization. If approved illuminate the green bulb. If disapproved illuminate the red bulb.