How secure is this modified Bazeries Cylinder?
How secure is this modified Bazeries Cylinder?


That depends on what you expect us to compare it to. I doubt you’re looking for an answer along the lines of “it’s more secure than Scytale, but less secure than AES”. Therefore, I will try to narrow it down a bit by saying that it is safe to assume it can not – in any way – provide the same security levels that modern cryptographic algorithms are able to provide. Some attacks are obvious; while others are merely a question of investing some time and effort to practically cryptanalyze the nitbits.


  My question is, could this coding system be broken by other than brute force methods ( which would be very tedious and expensive ) ?


Yes, it can. Mentioning only two of many examples: it definitely won’t hold for a second when applying a chosen-plaintext-attack or a known-plaintext-attack – which would both count as “valid breaks”.

Don’t get me wrong. It’s a nice design and it surely baffled some adversaries back in the days. Yet, in a (let’s just call it) “near-quantum” world, the cryptographic attractiveness  of this classical-cipher is nothing more than dust in the wind… a distant reminder of days where things like computers did not exist and security was easier to achieve and uphold.