encryption vs mystery

encryption

noun
  • The process of obscuring information to make it unreadable without special knowledge, key files, or passwords. 

  • A ciphertext, a cryptogram, an encrypted value. Usually used with the preposition "of" followed by the value that is hidden in it. 

mystery

noun
  • Something secret or unexplainable; an unknown. 

  • Someone or something with an obscure or puzzling nature. 

  • A religious truth not understandable by the application of human reason alone (without divine aid). 

  • A particular event or series of events in the life of Christ. 

  • A sacrament. 

  • A secret religious celebration, admission to which was usually through initiation. 

  • A craft, art or trade; specifically a guild of craftsmen. 

How often have the words encryption and mystery occurred in a corpus of books? (source: Google Ngram Viewer )