This is a super hard cipher to break.  It’s encoded by taking pairs of letters and numbers from a matrix. There are three rules to follow.


  1. If both letters are in the same row, then use the letters immediately to the right of each other. (Think of the rows as wrapping from the right end back around to that same row’s left end).
  2. If both letters are in the same column, then use the letters immediately below them. If necessary, the bottom letter wraps back around to the top of the same row.
  3. If the two letters or numbers are in different rows and in different columns, then each letter is replaced by the letter in the same row that’s also in the same column of the other letter. Basically, you find each intersection of the pair. Use the letter or number below the pair and then the one above the pair.

Play Fair sounds really complicated, but that also makes it a tough code to crack! Watch the video and I’ll explain it all for you.


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Comments

2 Responses to “Playfair Cipher”

  1. Gabriel Perdomo says:

    for ‘at’ you put a3 insted of 3a

  2. Dear Aurora,
    Some of my answers to the exercises were wrong, but I worked them out again, and three came out the same!
    One, I figured out, was due to the fact that there are two “A”s on your table, but the other two, I have done three times and still get the same result. On Q7, the first two letters, “GO”, I always get “SX”, rather than “XS”, as is on your answer sheet.
    On Q8, the fourth pair of letters always come out “3E”, rather than “MI”. Can you please have a look and tell me what I’m doing wrong?
    Thanks, Bubblepop.