7400 project encrypts and decrypts data

[Nakul], [Nikilesh], and [Nischal] just finished posting about their entry in the 2012 Open 7400 Logic competition. It’s an encryption system based entirely on 7400 logic chips. The device operates on 8-bit binary numbers, which limits its real-world applications. But we bet they learned a lot during the development process.

The encryption algorithm is based on a the concept of cellular automaton. This is a something with which we’re already familiar having seen many Conway’s Game of Life projects around here. What we’re not familiar with is this particular wing of the concept called ‘Rule 30‘. It works well with this project because a complex pattern can be generated from simple beginnings.

After conceptualizing how the system might work the team spent some time transferring the implementation to the chips they had available. The end result is a quartet of chip-packed breadboards and a rat’s nets of wires, but the system is capable of both encrypting and decrypting data.

Comments

  1. YT2095 says:

    their chip marked 74154 should be 74138 by the look of the pinout and truth table.
    just sayin` ;)

    Great work though! love the ZIF breakout unit, did you make it or buy it?

  2. Alex Rossie says:

    I don’t see why this being 8 bit is limiting any way :/
    You can break anything into bytes, otherwise computers would not work as we know them.

  3. ChalkBored says:

    It’s limiting because the key size is only 8 bits.

    • Alex Rossie says:

      So? It’s using a XOR cipher, as far as I can see, this could be used to implement an OTP each byte being XOR’d with a byte.

      It features the ability to use short keys with key lengthening to provide some protection from the weakness of reused keys in XOR ciphers. (No one is forcing you to use all these weaker key bits).

      Very very nifty…

  4. Admin says:

    The ZIF breakout-board..that is available in our lab..we are engineering students by the way..we tried implementing it on the ‘trainer kits’ initially (thats what we call them). But each kit holds only 5 chips. So, 4 kits and a huge mess of wires..unbelievably difficult to debug. So we switched to breadboards instead.

  5. Admin says:

    The ZIF breakout-board,we call it as ‘trainer kits’. it is available in our lab (we are engineering students). We tried implementing the entire circuit in it. But each kit holds 5 chips and there was a huge mess of wires. Unbelievably difficult to debug. So we moved on to bread boards instead :)

  6. Admin says:

    well, admin is Nakul in this case :)

  7. John U says:

    Back in the day, telecomms encryption/scrambling units used nothing more than 7400 logic.

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