Smithy code

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The Smithy code is a series of letters embedded, as a private amusement, [1] within the April 2006 approved judgement of Mr Justice Peter Smith on The Da Vinci Code copyright case. It was first broken, in the same month, by Dan Tench, a lawyer who writes on media issues for The Guardian , after he received a series of email clues about it from Justice Smith. [2]

Contents

How the code works

The letters in question are part of the actual text of the judgement, but italicised in contrast to the rest of the text. The following sequence of unusually emphasised letters can be extracted from the judgement document:

s m i t h y c o d e J a e i e x t o s t g p s a c g r e a m q w f k a d p m q z v

The italicised letters only occur up to paragraph 43 (which is page 13 of a 71-page document). Meanwhile, paragraph 52 concludes with this sentence: "The key to solving the conundrum posed by this judgment is in reading HBHG and DVC." (These abbreviations are used by Smith throughout the judgement in referring to the books at issue, The Holy Blood and the Holy Grail and The Da Vinci Code .)

There are 70 sections in the judgement. The source words from the judgement for the letters (with intervening words removed):

Claimants claimant is that his realitycynicism for preceded templar

Jersey able research this techniques extinguished technical story wasthe something groups used was documents being eradicated elsewhere Templars Claimants sequence with ofkey Plantard introduced manuscripts ultimately questions emblazoned prevalent

Letter frequencies

Excluding leading letters "s m i t h y c o d e", the letter frequencies are as follows:

Letter location

Paragraph numbers for cipher letters: [1]

Hints

From article "'Da Vinci' judgement code puzzles lawyers":

The New York Times reported that Smith sent an e-mail to a reporter at the newspaper that offered a hint. It said the code referred to his entry in this year's edition of Britain's "Who's Who," which has references to his wife Diane, his three children Frazier, Parker, and Bailey, British naval officer Jackie Fisher, and the Titanic Historical Society – among other things. [3]

Solution

The cipher was a type of polyalphabetic cipher known as a Variant Beaufort, using a keyword based on the Fibonacci sequence, namely AAYCEHMU. This is the reverse of the Vigenère cipher, which here enables decryption rather than encryption.

Jackie Fisher, Captain R.N. 1883, later First Sea Lord 1904-1910, 1914-1915 Admiral John Fisher.jpg
Jackie Fisher, Captain R.N. 1883, later First Sea Lord 1904–1910, 1914–1915

Assigning each letter its place in the alphabet, the keyword corresponds to 1, 1, 25, 3, 5, 8, 13, 21. It is possible that the reason 25 (Y) was included is to denote a backward step of 2 rather than a forward step. It is a twist drawn from The Holy Blood and the Holy Grail, and concerns the number 2 in the Fibonacci series, which becomes a requirement to count two letters back in the regular alphabet rather than a signal to use an alphabet that begins with B. For instance, the first E in the coded message, which corresponds to a 2 in the Fibonacci series, becomes a C in the answer.

The 10th ciphertext letter, T, should really be an H, and there should also be a Z at the end of the ciphertext.

The repetition of the digraph 'MQ', after 8 letters, suggested a key that was 8 letters long, which is in fact the case. (This type of attack on a cipher is known as a Kasiski test).

The full plaintext should read:

JACKIEFISHERWHOAREYOUDREADNOUGHT, ("Jackie Fisher who are you? Dreadnought")

Although correct application of the cipher in reverse, to decrypt, actually yields:

JACKIEFISTERWHOAREYOUDREADNOUGH

The algorithm for generating the plaintext from the ciphertext is: repeating the eight-letter key, add the relevant key letter to each plaintext letter, and then take a step one letter back.

(Alternatively, as is done in a professional context, the letters of the alphabet may be numbered from 0, in which case the final step back does not have to be made).

Jackie Fisher was a British admiral. "He was a driving force behind the development of the fast, all big-gun battleship, and chairman of the Committee on Designs which produced the outline design for the first modern battleship, HMS Dreadnought."[ citation needed ]

Related Research Articles

In cryptography, a substitution cipher is a method of encrypting in which units of plaintext are replaced with the ciphertext, in a defined manner, with the help of a key; the "units" may be single letters, pairs of letters, triplets of letters, mixtures of the above, and so forth. The receiver deciphers the text by performing the inverse substitution process to extract the original message.

<span class="mw-page-title-main">Transposition cipher</span> Method of encryption

In cryptography, a transposition cipher is a method of encryption which scrambles the positions of characters (transposition) without changing the characters themselves. Transposition ciphers reorder units of plaintext according to a regular system to produce a ciphertext which is a permutation of the plaintext. They differ from substitution ciphers, which do not change the position of units of plaintext but instead change the units themselves. Despite the difference between transposition and substitution operations, they are often combined, as in historical ciphers like the ADFGVX cipher or complex high-quality encryption methods like the modern Advanced Encryption Standard (AES).

<span class="mw-page-title-main">Caesar cipher</span> Simple and widely known encryption technique

In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code, or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of 3, D would be replaced by A, E would become B, and so on. The method is named after Julius Caesar, who used it in his private correspondence.

<span class="mw-page-title-main">Vigenère cipher</span> Simple type of polyalphabetic encryption system

The Vigenère cipher is a method of encrypting alphabetic text where each letter of the plaintext is encoded with a different Caesar cipher, whose increment is determined by the corresponding letter of another text, the key.

<span class="mw-page-title-main">Autokey cipher</span> Classic polyaphabet encryption system

An autokey cipher is a cipher that incorporates the message into the key. The key is generated from the message in some automated fashion, sometimes by selecting certain letters from the text or, more commonly, by adding a short primer key to the front of the message.

<span class="mw-page-title-main">Tabula recta</span> Fundamental tool in cryptography

In cryptography, the tabula recta is a square table of alphabets, each row of which is made by shifting the previous one to the left. The term was invented by the German author and monk Johannes Trithemius in 1508, and used in his Trithemius cipher.

<span class="mw-page-title-main">Frequency analysis</span> Study of the frequency of letters or groups of letters in a ciphertext

In cryptanalysis, frequency analysis is the study of the frequency of letters or groups of letters in a ciphertext. The method is used as an aid to breaking classical ciphers.

<span class="mw-page-title-main">Playfair cipher</span> Early block substitution cipher

The Playfair cipher or Playfair square or Wheatstone–Playfair cipher is a manual symmetric encryption technique and was the first literal digram substitution cipher. The scheme was invented in 1854 by Charles Wheatstone, but bears the name of Lord Playfair for promoting its use.

<span class="mw-page-title-main">Ciphertext</span> Encrypted information

In cryptography, ciphertext or cyphertext is the result of encryption performed on plaintext using an algorithm, called a cipher. Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext that is unreadable by a human or computer without the proper cipher to decrypt it. This process prevents the loss of sensitive information via hacking. Decryption, the inverse of encryption, is the process of turning ciphertext into readable plaintext. Ciphertext is not to be confused with codetext because the latter is a result of a code, not a cipher.

<span class="mw-page-title-main">Rotor machine</span>

In cryptography, a rotor machine is an electro-mechanical stream cipher device used for encrypting and decrypting messages. Rotor machines were the cryptographic state-of-the-art for much of the 20th century; they were in widespread use in the 1920s–1970s. The most famous example is the German Enigma machine, the output of which was deciphered by the Allies during World War II, producing intelligence code-named Ultra.

The affine cipher is a type of monoalphabetic substitution cipher, where each letter in an alphabet is mapped to its numeric equivalent, encrypted using a simple mathematical function, and converted back to a letter. The formula used means that each letter encrypts to one other letter, and back again, meaning the cipher is essentially a standard substitution cipher with a rule governing which letter goes to which. As such, it has the weaknesses of all substitution ciphers. Each letter is enciphered with the function (ax + b) mod 26, where b is the magnitude of the shift.

In cryptography, the ADFGVX cipher was a manually applied field cipher used by the Imperial German Army during World War I. It was used to transmit messages secretly using wireless telegraphy. ADFGVX was in fact an extension of an earlier cipher called ADFGX which was first used on 1 March 1918 on the German Western Front. ADFGVX was applied from 1 June 1918 on both the Western Front and Eastern Front.

In classical cryptography, the bifid cipher is a cipher which combines the Polybius square with transposition, and uses fractionation to achieve diffusion. It was invented around 1901 by Felix Delastelle.

In cryptography, a classical cipher is a type of cipher that was used historically but for the most part, has fallen into disuse. In contrast to modern cryptographic algorithms, most classical ciphers can be practically computed and solved by hand. However, they are also usually very simple to break with modern technology. The term includes the simple systems used since Greek and Roman times, the elaborate Renaissance ciphers, World War II cryptography such as the Enigma machine and beyond.

<span class="mw-page-title-main">M-209</span> Mechanical cipher machine

In cryptography, the M-209, designated CSP-1500 by the United States Navy is a portable, mechanical cipher machine used by the US military primarily in World War II, though it remained in active use through the Korean War. The M-209 was designed by Swedish cryptographer Boris Hagelin in response to a request for such a portable cipher machine, and was an improvement of an earlier machine, the C-36.

<span class="mw-page-title-main">Jefferson disk</span> Cipher system invented by Thomas Jefferson

The Jefferson disk, also called the Bazeries cylinder or wheel cypher as named by Thomas Jefferson, is a cipher system using a set of wheels or disks, each with the 26 letters of the alphabet arranged around their edge. The order of the letters is different for each disk and is usually ordered randomly. Each disk is marked with a unique number and a hole in the center of the disks allows them to be stacked on an axle. The disks are removable and can be mounted on the axle in any order desired. The order of the disks is the cipher key, and both sender and receiver must arrange the disks in the same predefined order. Jefferson's device had 36 disks.

The trifid cipher is a classical cipher invented by Félix Delastelle and described in 1902. Extending the principles of Delastelle's earlier bifid cipher, it combines the techniques of fractionation and transposition to achieve a certain amount of confusion and diffusion: each letter of the ciphertext depends on three letters of the plaintext and up to three letters of the key.

The four-square cipher is a manual symmetric encryption technique. It was invented by the French cryptographer Felix Delastelle.

The Two-square cipher, also called double Playfair, is a manual symmetric encryption technique. It was developed to ease the cumbersome nature of the large encryption/decryption matrix used in the four-square cipher while still being slightly stronger than the single-square Playfair cipher.

<span class="mw-page-title-main">Alberti cipher</span> Polyalphabetic substitution encryption and decryption system

The Alberti Cipher, created in 1467 by Italian architect Leon Battista Alberti, was one of the first polyalphabetic ciphers. In the opening pages of his treatise De componendis cifris he explained how his conversation with the papal secretary Leonardo Dati about a recently developed movable type printing press led to the development of his cipher wheel.

References

  1. 1 2 "Judge creates own Da Vinci code". BBC News . April 27, 2006. Archived from the original on September 5, 2007. Retrieved April 28, 2006.
  2. ↑ Tench, Dan (April 28, 2006). "How judge's secret Da Vinci code was cracked". The Guardian . Archived from the original on May 4, 2006. Retrieved April 28, 2006.
  3. ↑ Kravitz, Derek (April 27, 2006). "'Da Vinci' judgement code puzzles lawyers". Seattle Post-Intelligencer . Retrieved April 28, 2006.
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