Cryptex

The word cryptex is a neologism coined by the author Dan Brown for his novel The Da Vinci Code, denoting a portable vault used to hide secret messages. It is a portmanteau of the words cryptology and 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) - although actually a codex is a flat book.

Following the model of "codex" which pluralises as "codices", "cryptex" is presumed to pluralise as "cryptices".

In the main part of Brown's novel, the characters (while pursued by various sinister agencies) are trying to access the secret to the Holy Grail by figuring out the passwords that will open two different cryptices, one hidden within the other to provide extra security.

Design and function

The (first) cryptex featured in the novel is described as a stone cylinder made up of "five doughnut-sized disks of marble that had been stacked and affixed to one another within a delicate brass framework"; end caps make it impossible to see inside the hollow cylinder. Each of the disks is carved with the entire alphabet, and since they can be rotated individually, the disks can be aligned to spell different five-letter words.

The cryptex works "much like a bicycle's combination lock", and if one arranges the disks to spell out the correct password, "the tumblers inside align, and the entire cylinder slides apart" (p. 200). In the inner compartment of the cryptex, secret information can be hidden, written on a scroll of thin papyrus wrapped around a fragile vial of vinegar as a security measure: if one does not know the password but tries to pry the cryptex open by force, the vial will break and the vinegar will dissolve the papyrus before it can be read.

Would a cryptex work in real life?

It is not clear how effective vinegar would really be for dissolving the papyrus. While liquids certainly damage ancient documents, they would not necessarily render them instantly illegible. See [1] (http://germa.germsem.uni-kiel.de/gotisch/gissensis.html) for a Gothic document which was immersed in a flood.)

A cryptex would provide poor security in the modern-day world. Modern scanning methods (e.g. ultrasound or X-rays) could be used to display the inner mechanisms of the cryptex, revealing how it must be aligned to open it. Another possibility, which never occurs to the characters of Brown's novel, would be simply to place the cryptex in a freezer so that the vinegar freezes to ice. (The freezing point of vinegar depends on the strength of the solution, but is at most 2°C below zero.) Thereafter one could smash open the cryptex without risking that the vinegar would dissolve the papyrus hidden within.

A number of readers of the best-selling novel, wishing to construct a real cryptex, have tried to come up with the blueprints for one. It is claimed in the novel that the original design came from the secret diaries of Leonardo da Vinci; whether there is any basis for this claim remains undetermined. According to the Tacoma News Tribune, Justin Kirk Nevins, an inventor from Tacoma, Washington, has designed a functional cryptex and, as of January 2005, had sold 65 of them, including five to Dan Brown. However, he dropped the "self-destruct" mechanism involving the vial of vinegar, since he "felt that the practicality of this feature is questionable". A similar device constructed entirely in wood is also available to purchase, first handcrafted by Carlos de la Huerga for his own daughter's 9th birthday in Wisconsin.

It is not clear how effective vinegar would really be for dissolving the papyrus. While liquids certainly damage ancient documents, they would not necessarily render them instantly illegible. See [1] (http://germa.germsem.uni-kiel.de/gotisch/gissensis.html) for a Gothic document which was immersed in a flood.)

A cryptex would provide poor security in the modern-day world. Modern scanning methods (e.g. ultrasound or X-rays) could be used to display the inner mechanisms of the cryptex, revealing how it must be aligned to open it. Another possibility, which never occurs to the characters of Brown's novel, would be simply to place the cryptex in a freezer so that the vinegar freezes to ice. (The freezing point of vinegar depends on the strength of the solution, but is at most 2°C below zero.) Thereafter one could smash open the cryptex without risking that the vinegar would dissolve the papyrus hidden within.

A number of readers of the best-selling novel, wishing to construct a real cryptex, have tried to come up with the "blueprints" (http://www.blueprints.org) for one. It is claimed in the novel that the original design came from the secret diaries of Leonardo da Vinci; whether there is any basis for this claim remains undetermined. According to the Tacoma News Tribune, Justin Kirk Nevins, an inventor from Tacoma, Washington, has designed a functional cryptex and, as of January 2005, had sold 65 of them, including five to Dan Brown. However, he dropped the "self-destruct" mechanism involving the vial of vinegar, since he "felt that the practicality of this feature is questionable". A similar device constructed entirely in wood is also available to purchase, first handcrafted by Carlos de la Huerga for his own daughter's 9th birthday in Wisconsin.

External links

• "Cryptex security boxes" (http://www.cryptex.org) — Nevin's real-world cryptices.
• "Encrypta Cryptex" (http://www.encryptagifts.com) — by Innovator Carlos de la Huerga.