Signal Scrambler with ADC DAC

Nice idea

But only 24 different keys exist and this opens a brut force attack

Yes, and about half (11) of the keys are bad where most (2+) of the wires connect to the correct one rather than the wrong one. This could be improved by making a higher bit ADC-DAC combo. If it was a 256 bit one then it would literally be as strong as the 256 bit version of the AES (Advanced Encryption Standard) which is used for “sensitive” government files. I even read somewhere that it was authorized for use with “SECRET” and “TOP SECRET” files.

Hmmm, 100% biterror rate is somewhow the inverted signal and at least this key and key 0 are more or less useless, anyway you have to test them out of 24. But when you start with a 256bit adc, I must say stop! Think about a 26 bit ADC. Wasn't that a number you love? Suppose 1V input analog divided by 67108864 are about 15nV staircase steps! Realistic? No. Not to talk about 2^256 = 1e77 steps. AES does work completely different. Read a little more about CRC codes, this will help you to better understand.

Hmm, I suppose that does pose a bit of a problem. Even if you could manage a 16bit ADC then that would be only 65536 possibilities which leaves it wide open for brute force attack while having a step of 15uV. I suppose that it would be much better if you just had a regular ADC with no signal scrambling and then encoded the 4 or 8 bit signal with an encoding algorithm such as the AES I mentioned earlier.

You are to close to the communication link layer. Ciphering is done on a higher more abstract level. Have you ever heared about ISO-OSI 7 Layer model?

No, I haven’t.

But it sounds like for IDIOTS --- "If it was a 256 bit one then it would literally be as strong as inputthe 256 bit version of the AES (Advanced Encryption Standard)" ---

I don’t get your point.

You try to tell us that you know how AES works. But its obvious you have no idea. I hate that.

The way it works is that you create a key and then you put it together with a message in an encoding program and the program does some fancy stuff with the two like multiplicative inverses and scrambling and stuff based on the exact key to give you a highly encrypted output. For decoding you take the encoded message and put it together with the right key in the decoder program and then then it does some more fancy stuff like unscrambling and multiplicative inverses and stuff based on the exact key which when done with the right key results in the correct message.

Thats what scrambling is, not just AES. Question, what is the perfect scrambling?

I’d say that the perfect scrambling is a scrambling that scrambles the input into a completely different output for each key and neither the key nor the input can be found by looking at just the output.

Yeah, now we could talk about what you mean with "completely different", but anyway. Only one hint, think about 100% inverted (or bit error) is maybe for you "completely different". But is this really scrambled? Ok, forget that. What you need for a perfect ciphered link is: make a long key, put it on a memory stick and take care that only you and your friend has access to this key data. Any data you transfer to your friend will be bitwise XOR'ed with the key, and your friend knows the key. To decode he XORed again and can read you original. Thats what you also said. Any used key must be wasted, can not be reused! The key data must be "perfectly" random. This is a perfect way to scramble. Not to complicated. But not very practical, cause the size of the memory stick would be the limit for you and your friend. And you need for all friends an extra key. And what is you cant exchange the key physicaly? All this is what AES makes more practical, cause they have methodes to come over these limits. But for the price of security. For example, to transfer the key, only a little part is transfered, the sequence is then generated by some kind of CRC mixers and registers to generate an non periodic bit stream (which looks as random as possible). The key is only the start value of this super long sequence generators.