where, in your opinion, should a total beginner to cryptography start in their attempt to learn it?
Simon Singh’s The Code Book, which your local library should have. Followed by whatever other free books you can get your hands on (libraries, Amazon giveaways, etc.) I say this because I’ve read a lot classical crypto books, and many of them are just rehashes of each other, with no new insight. Also my thanks for asking tag, where I’ve answered similar questions, sometimes better or for worse, depending on how you catch me.
And then, when you’re reading some book and the author is explaining something, say frequency analysis, take an hour or so to try it. Some of these books have practice ciphers, there are ones available online, I’ll send you one if you need it, and then actually do the steps with pen and paper, or by programming it if you’re so inclined, and solve it. That’s really the best way to learn.
“Lh amk hjxk J hsacesh hsk xazh jxyaghlmh hsjme olz hlqkmh. J hsjmd mao hslh — hsk facme xlm ag hsk facme oaxlm xczh yazzkzz ag hklws sjxzkqt, hgljm sjxzkqt, jm jmtjmjhk ylhjkmwk, osjws jz ha hgf lmv ha hgf lmv ha hgf cmhjq jh waxkz gjesh.” – Ojqqjlx Tlcqdmkg
Try it. Count up, for each letter in this cipher, how many times it occurs (some word processors can be helpful for this, and there are specialized tools online to do this drudge work.) Then take a guess that the most common letter in the cipher is E, the most common letter in English, and see if spelling out a second copy with the E’s marked gives you any clues about other words (zqE might be THE, for example.) But remember it’s all guess work, and averages. The most common letter in English, on average is E, but in this quote it might be T, or something weirder. If you guess incorrectly, go back and try again, and again, checking each time to see if you seem to be getting closer or further from your goal.
Also remember that there’s no cheating or wrong way to get the answer in cryptography. You might look at the quoted person’s name, Ojqqjlx, and suddenly guess what it is because you have a friend with the same name. After doing this a long time, I sometimes see patterns, like 1234 34 125, and recognize it as the common phrase THIS IS THE. When you get into harder, polyalphabetic ciphers, the techniques will be more abstract, as the patterns in the cipher will also be, but it’s still a combination of techniques, intuition, and trial and error that gets you across the finish line.
