the word cryptex is a neologism coined by the author dan brown for his 2003 novel "the da vinci code", denoting a portable vault used to hide secret messages. it is a word formed from greek "kryptós", "hidden, secret" and latin "codex"; "an apt title for this device" since it uses "the science of "cryptology" to protect information written on the contained scroll or "codex"" (p. 199 of the novel). the first physical cryptex was created by justin kirk nevins in 2004.