Having A Crack At Passwords

The password module can be time consuming when done normally without any improvement method. And no matter what method you choose (including this one) to make it go smoother there will always be that luck factor given the module's nature. You could always memorize the whole table but that is no fun! This guide is an attempt to make things smoother.

This guide is currently made for bomb manual Version 1 Revision 2.

Generally all methods follow some kind of process of elimination, this one comes with a diagram to help facilitate this process, as shown below:

It might look scary at first, but do give it a try. Here's how it works:

• You the expert should have the diagram opened in a painting program (or have it printed and a pencil ready).
  
• Ask the defuser to name the 5th letters of the module, since all positions have 6 letters, it might help to say them in groups of 3 e.g. abc-def.
  
• As you hear the letters, mark or circle any letters that exist under the column named 5th.
  
• After you are done marking, the letters in that column that weren't marked will have all the words to their right eliminated by default. Depending on the number of words remaining, you are free to take guesses at the remaining words and eliminating ones that don't fit (e.g. if defuser says the word you gave him does not have u at 3rd letter, then all words that have u in 3rd letter are eliminated), or you can proceed to the next steps to try and further sift the list by using the column named 3rd.
  
• Ask the defuser to name the 3rd letters, marking the ones you hear that do exist under the column 3rd.
  
• After you are done marking, start tracing from the letters that you marked at 5th to see how many of their lines end up at a marked letter in the 3rd column. For example, if you had d marked in the 5th column then:
  
  • If neither of r or u are marked in the 3rd column, then the words to the right of d are eliminated.
    
  • if r is marked, then all words to the right of d that have u in their 3rd letter are eliminated. (Notice that all the words to the right are sorted by 3rd letter and are also grouped by 3rd letter.)
    
  • if both are marked, then no words can yet be eliminated with certainty.
• If you reach this point and there are still too many words remaining you will have to start taking educated guesses and eliminate as necessary. For example you can now start asking for first letters as well and choose words accordingly.

And that's pretty how much how this method works, please let me know if it came in handy. Below are details of my thought process for the technically inclined.

This section is only for those what want to know how I came up with this method in hopes of further improving it or just out of curiousity.

• Why the 3rd and 5th letters?
  When I counted the number of unique letters for each position in the list, the 3rd and 5th came with the least number, namely 11 letters. Other positions gave either 14 or 15. That doesn't necessarily mean they are the best, think of it as a heuristic.
  
• What made you come up with this method?
  Originally I wanted to make use of some kind of decision tree, but the problem is unlike the morse module even if the first letter for example is a letter used in the list that doesn't necessaily mean the correct word starts with it. So I had to think more along the lines of paths instead of trees. Originally I made a diagram of all 5 positions, it wasn't pretty and most of the time I didn't need more than the last two columns.
  
• Why are the lines colored?
  When the diagram was plain black & white it was hard to trace the lines, but I also thought it would get hard to trace with too many color so I arbitrarily chose red, blue & green. Sorry if you have some color blindness between some of them, feel free to edit.
  
• The design could use an improvement
  I'm not a designer myself so I am open to suggestions. (・ω・｀)