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Smithy code

Smithy code is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Smithy code rather than just read about it. In short: The Smithy code is a series of letters embedded, as a private amusement, within the April 2006 approved judgement of Mr Justice Peter Smith on The Da Vinci Code copyright case. The judge publicly admitted that "I can't discuss the judgement, but I don't see why a judgement should not be a matter of fun." It was first broken, in the same month, by Dan Tench, a lawyer who writes on media issues for The Guardian, after…

Smithy code — main illustration
Smithy code — illustration

Key takeaways

  • Smithy code belongs to computer science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Smithy code to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Smithy code from memory before moving on to harder problems.

Reference excerpt

The Smithy code is a series of letters embedded, as a private amusement, within the April 2006 approved judgement of Mr Justice Peter Smith on The Da Vinci Code copyright case. The judge publicly admitted that "I can't discuss the judgement, but I don't see why a judgement should not be a matter of fun." 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.

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 reality cynicism for preceded templar Jersey able research this techniques extinguished technical story was the something groups used was documents being eradicated elsewhere Templars Claimants sequence with of key 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:

a – 4 e – 3 g, m, p, q, s, t – 2 c, d, f, i, j, k, o, r, v, w, x, z – 1

Letter location Paragraph numbers for cipher letters:

1 Claimant(s) 2 clai(m)ant 3 (i)s (t)hat [...] (h)is [...] realit(y) 4 (c)ynicism 5 f(o)r 6 prece(d)ed 7 T(e)mplar 8 New (J)ersey [...] (a)ble 9 res(e)arch 11 th(i)s [...] techniqu(e)s 13 e(x)tinguished 14 (t)echnical 16 st(o)ry [...] wa(s) 18 (t)he 19 somethin(g) 20 grou(p)s 21 u(s)ed 23 w(a)s 25 do(c)uments [...] bein(g) [...] e(r)adicated 26 elsewh(e)re 27 Templ(a)rs 29 Clai(m)ants [...] se(q)uence 30 (w)ith 31 o(f) 34 (k)ey 35 Plant(a)rd 37 intro(d)uced 38 manuscri(p)ts 40 ulti(m)ately 42 (q)uestions 43 embla(z)oned [...] pre(v)alent

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.

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.

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") However, 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."

References

External links The complete text of the judgment was formerly available at http://www.hmcourts-service.gov.uk/images/judgment-files/baigent_v_rhg_0406.pdf. The archived copy of this text from 5 December 2006 can be found here Baigent v Random House [2006] EWHC 719 (Ch) (7 April 2006), text of the judgment without the italics that mark out the cyphertext. Famous Unsolved Codes (lists the Smithy Code as solved) Kryptos Group report - analyzes how the code is put together, and contains a link to a mirrored copy of the PDF of the original judgment Hoyle, Ben (April 28, 2006). "A nudge from the Da Vinci judge to help you to crack his code". The Times. London. Retrieved April 28, 2006.{{cite news}}: CS1 maint: deprecated archival service (link) Hoyle, Ben (April 28, 2006). "How I cracked the Smithy code (with a little help from the judge)". The Times. London. Retrieved April 28, 2006. Tool to crack the code

Worked examples

Example 1 — a first encounter with Smithy code

Start with the simplest possible case. Write down what Smithy code claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Smithy code before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Smithy code ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Smithy code

In research
Smithy code appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Smithy code in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Smithy code is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2006 in British law, 2006 in the United Kingdom, History of cryptography, so understanding it makes those chapters shorter.
In everyday life
Look for Smithy code outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Smithy code in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Smithy code means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Smithy code out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Smithy code in simple terms?

The Smithy code is a series of letters embedded, as a private amusement, within the April 2006 approved judgement of Mr Justice Peter Smith on The Da Vinci Code copyright case. The judge publicly admitted that "I can't discuss the judgement, but I don't see why a judgement should not be a matter of…

Why does Smithy code matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Smithy code?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Smithy code.

Tags

  • 2006 in British law
  • 2006 in the United Kingdom
  • History of cryptography
  • Puzzles
  • The Da Vinci Code

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