What does a Caesar cipher do?
AnswerShifts each letter by a fixed number
A Caesar cipher moves letters a set distance along the alphabet.
Tech · Facts & stats
Hacking facts & stats
7 fact-checked facts about ciphers, cryptography and capture-the-flag puzzles, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
Which German cipher machine was broken by Allied codebreakers in WWII?
AnswerEnigma
Breaking Enigma gave the Allies vital intelligence.
Going deeper
Which mathematician was central to breaking Enigma at Bletchley Park?
AnswerAlan Turing
Turing designed the Bombe to speed up Enigma decryption.
Base64 is best described as what?
AnswerAn encoding, not encryption
Base64 is easily reversed and offers no secrecy.
Hiding a message inside an image or other file is called what?
AnswerSteganography
Steganography conceals that a message exists at all.
Expert level
In what year did NIST adopt AES as a standard?
Answer2001
AES, based on Rijndael, became a US standard in 2001.
Which cipher is provably unbreakable when used correctly?
AnswerThe one-time pad
A truly random, never-reused key as long as the message cannot be cracked.
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