I’ve googled this out of curiosity and it seems that over the years various people have attempted brute force solutions to the z340 with no success.
As someone with no cipher knowledge/experience I find it disheartening that, if it was done properly, a brute force approach hasn’t yielded any results. I would appreciate it if one of the regular cipher posters could explain in layman’s terms if there’s types of encryption that are resistant to this kind of decoding? I would imagine only a unique-symbol-per-character cipher would be completely resistant, but if it was one of those I also imagine it would be impossible to verify any ‘solution’ where the code never recycles a symbol.
Further, does anyone know if there is any continuous brute force decoding being attempted? It would be nice to know that someone, somewhere has a pc running this 24/7 and will eventually have an answer.
Check out my website: www.darkideas.net
With current computing technology, a brute force examination of all possible keys for Z340 is not possible.
Let’s assume we are talking about simple substitution keys. Z340 has 63 unique symbols, so under this assumption, each symbol is assigned to one of 26 letters of the alphabet.
Since you have to test all 26 letters for the first symbol, and all 26 letters for the second, and so on for all 63, that means there are this many combinations to test: 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26 X 26
That 26 raised to the 63rd power, which is this humongous number: 139,098,011,710,742,195,590,974,259,094,795,403,842,655,842,142,490,330,518,716,727,403,333,474,672,708,595,090,456,576
The fastest supercomputer in the world is a Chinese one called "Sunway TaihuLight" which is rated at 93 "petaFLOPS". FLOPS stands for "floating point operations per second". Now let’s assume that testing a single key costs a single floating point operation. Then, a computer that can handle 93 petaFLOPS means it can test 93 thousand million million (93,000,000,000,000,000) keys per second.
So how long would Sunway TaihuLight take to examine 139,098,011,710,742,195,590,974,259,094,795,403,842,655,842,142,490,330,518,716,727,403,333,474,672,708,595,090,456,576 key combinations? Answer: About 47,400,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 years.
If you had a trillion of those super computers running tests at the same time, it would still take 47,400,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 years.
Therein lies the problem! And, even if you could pull that off, you might still turn up short because Z340 is likely not a simple substitution cipher. If there’s some kind of transposition going on before the symbols are assigned, then you have to include all possible transposition types to the search. If you wanted to test a thousand different kinds of transposition, then the number of keys would be that bigass number multiplied by itself a thousand times. YUCK!
BUT, on the other hand, you can brute force smaller problems. For example, you could look at a smaller section of Z340. Here’s a section that has 25 symbols but only 16 of them are unique: RcT+L16C<+FlWB|)L++)WCzWc
If you tested all 26^16 keys for that little section, the Chinese supercomputer could brute force through all of them in a little over five days.
Wow, thank you for the response. It’s really surprising that something that looks as ‘small’ as the z340 in data terms can actually be hiding a problem of such epic proportions. That certainly explains why brute force hasn’t worked yet, and won’t for some time to come by the looks of it. So, if I understand correctly, the most efficient process available is to pick a suitable section and then extrapolate any successful results over the rest of the code. It will be interesting to see who gets there first; man or machine?
I enjoyed your 2015 symposium video, do you plan on recording this year’s one?
Check out my website: www.darkideas.net
Brute force on a section could be fruitful, but there are many non-brute force approaches that are very effective on substitution ciphers because they take advantage of language statistics. Z340 has not been vulnerable to these approaches, very likely because it isn’t a simple substitution cipher, or its message is so unusual that its statistics are very different from normal language. The real trick is to answer the question: Did Z do something else to the message besides replace letters with symbols? If so, brute force will never find the solution unless the extra undiscovered step is accounted for.
I do intend to record this year’s video.
