A substitution cipher swaps every letter for another letter and keeps that swap for the whole message. The text still looks like text — same word lengths, same spacing, same doubled letters — it just isn't in English yet.
Word shapes survive. If you can see one- and two-letter words, an apostrophe, or the same letter doubled in the middle of a word, you are almost certainly looking at a substitution.
Keyword Cipher The alphabet starts with the keyword, then carries on with the letters it hasn't used.
TREASURE MAP
keyword GOLD
TRAGSURA KGP
Every letter has been swapped for another one, and the same swap is used all the way through. Letter shapes stay put — word lengths and spacing are still real clues. This one is Keyword Cipher. The key: keyword GOLD. The alphabet starts with the keyword, then carries on with the letters it hasn't used. Apply the key to the first three letters and they resolve to T R E. The answer was TREASURE MAP.
Start with the short words and the most common letter. In English that letter is usually E, and a lone letter is usually A or I. Two or three correct guesses tend to collapse the rest of the message on their own.
These have closed, so each one carries the full solution. Play them for practice — archive days never touch a streak.
Every letter has been swapped for another one, and the same swap is used all the way through. Letter shapes stay put — word lengths and spacing are still real clues. This one is Keyword Cipher. The key: keyword GOLD. The alphabet starts with the keyword, then carries on with the letters it hasn't used. Apply the key to the first three letters and they resolve to N O T. The answer was NOTHING VALUABLE IS EVER EASY TO FIND.
One a day, three guesses, and a streak that breaks the moment you miss one. Today’s is cipher #12.