The term cryptology comes from two words, meaning “hidden” and “word,” in what language?

What is the digraph substitution cipher cracked by Lord Peter Wimsey and Harriet Vane in Dorothy L. Sayers’s book Have His Carcase?

Who invented a type of simple polyalphabetic cipher that was once thought to be impregnable and hence was nicknamed “the indecipherable cipher”?

What is the best-known public-key scheme cryptoalgorithm?

What militaristic people employed a cipher device called the scytale for secret communication between army commanders as early as 400 BCE?

Who were the inventors of the first transposition cipher?

During the 4th century BCE who wrote On the Defense of Fortifications, one chapter of which was devoted to cryptography?

Which Greek inventor devised a means of encoding letters into pairs of symbols by using a device named after him?

Which ancient Roman cipher, using monoalphabetic substitution with a simple cyclic displacement of the alphabet, was named after a famous general and statesman?

HAL, the computer in the film 2001: A Space Odyssey (1968), encrypts to IBM using the cipher of which Roman emperor?

About 1412 which Egyptian scholar discussed several cryptographic systems in his encyclopaedia, Ṣubīal-aīshī?

Who authored the first European manual on cryptography (c. 1379), a compilation of ciphers that contains a set of keys for 24 correspondents as well as symbols for letters, nulls, and several two-character code equivalents for words and names?

Who wrote in 1466 or 1467 the treatise "De componendis cyfris" (Latin: "On Writing in Ciphers"), which presented the first polyalphabetic cipher?

What is the famous unsolved book cipher that purports to give the location of a buried treasure in Bedford county, Virginia?

Who was the chief codebreaker for British commander Arthur Wellesley, later 1st duke of Wellington, during the Peninsular War (1808–14)?

What was the brand name for a famous series of innovative electro-mechanical devices used by the German military during World War II to encode and decode its top-secret radio traffic?

What early electronic computer, invented by Royal Post Office engineer Tommy Flowers, was used to decipher complexly encoded teleprinter messages from Hitler and the German High Command, enabling the Allies to eavesdrop on the Germans before D-Day?

What algorithm, submitted by IBM, became the Data Encryption Standard (DES) for the U.S. National Bureau of Standards in 1975?

Which Native American language was used by U.S. Army units during World War I to transmit secret tactical messages and proved instrumental in a successful surprise attack against the Germans?

What code did Napoleon and his officers begin using in 1811 after their previous code was broken by British Army Major George Scovell?

What late 18th-century code, deciphered only in 2011, was used to mask a text describing a ritual of a secret society that apparently had a fascination with eye surgery and ophthalmology?

What is the name of an extraordinary codex from the 15th or 16th century that is filled with bizarre illustrations and text in a unique alphabet that no one has ever deciphered?

What is the name of the eight-letter carving of unknown meaning inscribed into the Shepherd’s Monument in Staffordshire, England?