What does ROT13 do to the letter A?
AnswerTurns it into N
ROT13 shifts each letter 13 places, so A becomes N.
Tech · Facts & stats
Hack facts & stats
7 fact-checked facts about codebreaking, ciphers and puzzle hacks, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
What is plaintext in cryptography?
AnswerThe original readable message
Encryption turns plaintext into ciphertext.
Going deeper
What technique breaks simple substitution ciphers by counting letters?
AnswerFrequency analysis
Common letters like E show up most often in English text.
What is the most common letter in typical English text?
AnswerE
E is the most frequent letter in English.
What is steganography?
AnswerHiding a message inside something else, like an image
Steganography conceals that a message exists at all.
Expert level
The Vigenere cipher uses what to vary its shifts?
AnswerA keyword
Each letter of a keyword sets a different Caesar shift.
What do the letters in RSA stand for?
AnswerRivest, Shamir and Adleman
RSA is named after its three inventors, who published it in 1977.
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