As it explained in the theory page, the modern word “crypto” is related to crypt from Christian terminology and originally to Phoenician Aleph letter ("𐤀"). Because people were unable to read texts with this letter and these letters were looking like eyelash which is “kirpik” in Turkish. They started calling those texts something like “kirpikted”. Over this, the term crypto evolved to refer encryption or concealment. The letter also look like a trimming tools which derives from the action of trimming in Turkish (Kırp-mak). Phoenician alphabet was replaced an possibly banned by Rome, around or before Common Era. Phoenician alphabet is also original alphabet used in Hebrew texts (Paleo-Hebrew) and around Common Era Jews switch to square alphabet but it is clear this wasn't voluntary because they use the old alphabet every time they rebel against the Rome. (Explained in Phoenician Alphabet page.)
In the introduction of one of his book from 1888 Max Muller states: “There is this ancient crypt underlying everywhere the ground-floor of our language, and though that crypt is often very troublesome to explore, very slippery and full of cobwebs, no one can any longer deny its existence, or doubt that it consisted of what, for want of a better name, we call roots.”. (Biographies of Words and the Home of the Aryas, pages: xi-xii)