Replies

Enigma was a simple XOR crypto system that required a truly random number generator and adherence to secure protocol to operate well... they had neither.

No programmed or mechanical system to generate random bits is possible, these are Pseudo-Random Number Generators (PRNG) it requires a quantum level source of randomness such as Brownian motion or something very simple like diode noise or a natural phenomenon like weather or cosmic background radiation sampling (TRNG)

When you are faced with breaking a crypto system that is well designed and implemented you must look to human failure to get into it...

Numbers stations that send out broadcasts to distant operatives are generally based on XOR principles and cannot be broken by any computational means, no matter how powerful... even a quantum qubit based system has zero chance of breaking a well executed XOR system... this is because ALL possible decryptions of the data are equally possible and the correct key cannot be determined by any computational means.

XOR methods are handicapped by the fact that the key MUST be generated by a quantum-level random bit sequence. The plaintext can be anything at all and matches the key in length. The system is unwieldly since you cannot possibly remember such a long key, thus it has to exist in the device that performs the encryption... but the introduction of cheap SD memory has mitigated this problem a great deal since it can hold an enormous number of bits that comprise XOR random keys and as the keys are used they can be instantly erased so the individual messages that are sent from such a device cannot EVER be recovered by technical means once the message is sent and received and the key is erased.

It is best to use XOR methods to transfer keys for Symmetric key algorithms such as AES instead of wasting your stored random data to transfer the actual plaintext. A device with just a few GB of random data can easily transfer a staggering amount of data with near absolute security... any security failure will be due to poor implementation and human factors.

The introduction of quantum computing will introduce weakness into public key crypto systems and we will have to resort to XOR methods for high-security applications even though such systems will require returning to the use of key exchanges to function... it is what it is :-( but large SD cards at least means the key exchange only need be done once since you can send an enormous number of symmetric keys with just a TB of random XOR key data... but the bank of XOR bits must remain secure!

Public key encryption is so handy! It will be difficult to abandon it for data requiring absolute security... it will still be suitable for everyday purposes that do not require a level of security that only a nation-state can break... i.e. the data can be decrypted by a major power but not by an individual or small group.. safe against crooks but not the government.