EURion constellation

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The EURion constellation is made up of five rings.
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The EURion constellation is made up of five rings.

The EURion constellation is a pattern of symbols found on a number of recent banknote designs. It is added to help software detect the presence of a banknote in a digital image. Such software can then block the user from reproducing banknotes to prevent counterfeiting using colour photocopiers.

Contents

[edit] Description

The small circles of the EURion constellation are clearly visible on the centre-left of 10 euro banknotes.
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The small circles of the EURion constellation are clearly visible on the centre-left of 10 euro banknotes.
On the Bank of England £20 the EURion constellation appears as "musical notes".
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On the Bank of England £20 the EURion constellation appears as "musical notes".

The name "EURion constellation" was coined by Markus Kuhn, who discovered the pattern in early 2002 while experimenting with a Xerox colour photocopier that refuses to reproduce banknotes. The word is a portmanteau of Orion, a constellation of similar shape, and EUR, the euro's ISO 4217 designation.

The EURion constellation first described by Kuhn consists of a pattern of five small yellow, green or orange circles, which is repeated across areas of the banknote at different orientations. The mere presence of five of these circles on a page is sufficient for some colour photocopiers to refuse processing. Andrew Steer later noted simple integer ratios between the squared distances of nearby circles, which gives further clues as to how the pattern is meant to be detected efficiently by image-processing software.

The EURion constellation is most prominent and was therefore first recognised on the 10 Euro banknote.

Some banks integrate the constellation tightly with the remaining design of the note. On German banknotes, the EURion circles formed the innermost circles in a background pattern of fine concentric circles. On the front of English £20 notes, they appear as green heads of musical notes. On U.S. dollar bills, they form the digit zero in little yellow numbers that show the value of the note.

Technical details regarding the EURion constellation remain kept secret by its inventors and users. A patent application suggests that the pattern and detection algorithm were designed at OMRON Corporation.

The EURion constellations lined in blue on a US $20 bill.
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The EURion constellations lined in blue on a US $20 bill.

[edit] Usage

The following table lists the banknotes on which the EURion constellation has been found so far:

Currency Notes with EURion constellation Notes without EURion
Armenian dram 1000 dram (2001), 5000 dram (2003), 10000 dram (2003) 20000 and commemorative 50000 dram
Aruban florin All (2003)
Austrian schilling 500 and 1000 schilling (1997) 20, 50, 100, and 5000 schilling
Australian dollar Commemorative $5 (2001) Regular banknotes
Belgian franc 500 francs (1998), 1000 francs (1997), 10000 francs (1997) 100, 200, and 2000 francs
British pound Bank of England £5 (2002), £10 (2000), £20 (1999) £50 (not yet upgraded)
Bulgarian lev All (1999)
Canadian dollar All (2001)
CFA franc All (both West African and Central African, 2003)
Chinese yuan ¥1 (2004), 2005 revision of ¥5 and above
Comorian franc 1000 and 2000 francs (2005) 500, 2500, 5000, and 10000 francs
Croatian kuna 5, 10, 20 kuna (2001), 50, 100, and 200 kuna (2002) 500 and 1000 kuna
Danish krone All (1997 and 2002 series)
Djiboutian franc 1000 francs (2005) 2000, 5000, and 10000 francs
Dutch gulden 10 gulden (1997) 25, 50, 100, 250, 1000 gulden
Egyptian pound LE 5 (2002), LE 10 (2003), LE 20 (2001), LE 50 (2001), LE 100 (2000) 25 piastres, 50 piastres, LE 1
Euro All (2002)
Faroese króna All (2001)
French franc 100 francs (1997) 50, 200, and 500 francs
German mark 50, 100, 200 mark (1996-2002) 5, 10, 20, 500, 1000 mark
Japanese yen Commemorative ¥2000 (series D, 2000), series E (2004)
Madagascan ariary 100, 200, 500, 1000 ariary (2004) 2000, 5000, 10000 ariary
Mexican peso $1000 (2004) $20, $50, $100, $200, $500
Moroccan dirham All (2002)
Netherlands Antillean gulden 10, 25, 50, 100 gulden (1998) 250 gulden (1986)
Norwegian krone All (1999)
Romanian leu All (2005)
Singapore dollar All (1999)
Slovak koruna 200, 500, 1000, and 5000 korún (1999) 20, 50, and 100 korún
South African rand All (2005)
South Korean won ₩1000 (2007), ₩5000 (2006), ₩10000 (2000 and 2007) ₩1000 (1983-2007)
Swedish krona Kr 50 (2006), Kr 100 (2001), Kr 500 (2001), Kr 1000 (2006) Kr 20
Tunisian dinar 10 dinars (2005) 5, 20, and commemorative 30 dinars
Turkish new lira All (2005)
United States dollar $5 (2008), $10 (2006), $20 (2003), $50 (2004), $100 (after new $5) $1, $2, $5 (-2008), $100

[edit] Other banknote detection mechanisms

Example of CDS anti-counterfeit measures operating on image editing software.
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Example of CDS anti-counterfeit measures operating on image editing software.

Users of recent versions of image editors, such as Adobe Photoshop or Paint Shop Pro, discovered that these also refuse to print banknotes. According to an article in Wired magazine, the banknote detection code in these applications, called the Counterfeit Deterrence System (CDS), was designed by the Central Bank Counterfeit Deterrence Group and supplied to companies such as Adobe as a binary module. However, experiments by Steven J. Murdoch and others showed that this banknote detection code does not rely on the EURion pattern. It instead detects a digital watermark embedded in the images, developed by Digimarc. (see Central Bank Counterfeit Deterrence Group)

[edit] References

[edit] External links

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