EURion constellation
The EURion constellation is a pattern of symbols incorporated into a number of secure documents such as banknotes and ownership title certificates designs worldwide since about 1996. It is added to help imaging software detect the presence of such a document in a digital image. Such software can then block the user from reproducing banknotes to prevent counterfeiting using colour photocopiers. According to research from 2004, the EURion constellation is used for colour photocopiers but probably not used in computer software. It has been reported that Adobe Photoshop will not allow editing of an image of a banknote, but in some versions this is believed to be due to a different, unknown digital watermark rather than the EURion constellation.
Description
The name "EURion constellation" was coined by security researcher Markus Kuhn, who uncovered the pattern on the :File:EUR 10 obverse.jpg|10 Euro banknote in early 2002 while experimenting with a Xerox colour photocopier that refused to reproduce banknotes. The word is a portmanteau of EUR, the euro's ISO 4217 designation, and Orion, a stellar constellation. The pattern bears a resemblance to the European Commission Berlaymont building in Bruxelles.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.
Some banks integrate the constellation tightly with the remaining design of the note. On 50 DM German banknotes, the EURion circles formed the innermost circles in a background pattern of fine concentric circles. On the front of former Bank of England Elgar £20 notes, they appear as green heads of musical notes; however, on the Smith £20 notes of 2007 the circles merely cluster around the "£20" text. On some U.S. bills, they appear as the digit zero in small, yellow numbers matching the value of the note. On Japanese yen, these circles sometimes appear as flowers.
Technical details regarding the EURion constellation are kept secret by its inventors and users. A 1995 patent application suggests that the pattern and detection algorithm were designed at Omron Corporation, a Japanese electronics company. It is also not clear whether the feature has any official name. The term "Omron anti-photocopying feature" appeared in an August 2005 press release by the Reserve Bank of India. In 2007 the term "Omron rings" was used in an award announcement by a banknote collectors society.
Usage
The following table lists the banknotes on which the EURion constellation has been found so far. Current currencies whose all recent banknotes use the constellation are in bold.| Currency | Notes with EURion constellation | Notes without EURion constellation |
| Armenian dram | 1000 ֏, 5000 ֏, 10,000 ֏, 20,000 ֏, 100,000 ֏ | 20,000 ֏ and commemorative 50,000 ֏ |
| Aruban florin | All | |
| Austrian schilling | 500 and 1000 schilling | 20, 50, 100, and 5000 schilling |
| Australian dollar | Centenary of Federation $5, "Next-Generation" $5, $10, $50, $20 | All other notes |
| Belgian franc | 500 francs, 1000 francs, 10,000 francs | 100, 200, and 2000 francs |
| British pound | Bank of England £5 £5, £10 £10, £20, £50 | £50 |
| Bosnia and Herzegovina convertible mark | 200 convertible marka, All | 50 feninga, 1, 5, 10, 20, 50, 100 convertible marka |
| Bulgarian lev | All, 100 leva | |
| Burmese kyat | K1,000, K500 | 50 pyas, K1, K5, K10, K20, K50, K100, K200, K500, K1000, K5000, K10,000 |
| Canadian dollar | Banknotes in the Canadian Journey and Frontier Series, "Canada 150" $10 $10 | |
| CFA franc | All | |
| Chilean peso | 1000 2000 5000, 10,000, 20,000 pesos | 1000 and 2000 pesos |
| Chinese yuan | ¥1, 2005 revision of ¥5 and above, ¥100, ¥1, ¥10, ¥20 and ¥50 | |
| Comorian franc | All | 2500 francs |
| Croatian kuna | 5, 10, 20 kuna, 50, 100, and 200 kuna | 500 and 1000 kuna |
| Czech koruna | 2000, 1000, 500, 5000, 100 and 200 | 100, 500, 1000, 5000 |
| Danish krone | All | |
| Djiboutian franc | 1000 francs, 2000 francs, 10,000 francs | 2000, 5000, and 10,000 francs |
| Dutch guilder | 10 gulden | 25, 50, 100, 250, 1000 gulden |
| Egyptian pound | LE 5, LE 10, LE 20, LE 50, LE 100, LE 200 | 25 piastres, 50 piastres, LE 1 |
| Euro | All | |
| Faroese króna | All | |
| French franc | 100 francs | 50, 200, and 500 francs |
| German mark | 50, 100, 200 Deutsche Mark | 5, 10, 20, 500, 1000 Deutsche Mark |
| Guyanese dollar | $1,000 | |
| Hungarian forint | All, 10,000 forint, 20,000 forint, 2,000 forint, 5,000 forint, 1,000 forint, 500 forint | |
| Indian rupee | 50, 100 and 500 , 500, 1000, 2000, 50, 200, 100 | 5, 10, 20, 50, 1st edition of 100 and 500 |
| Indonesian rupiah | All | |
| Japanese yen | ¥2000, series E, series F ; ¥1000 | |
| Kyrgyzstani som | All | |
| Kuwaiti dinar | All | |
| Macanese pataca | Banco Da China: All | |
| Malagasy ariary | 100, 200, 500, 1000, 2000, 5000, 10,000 ariary, All | 2000, 5000, 10,000 ariary |
| Mexican peso | Series D $1,000, All | $20, $50, $100, $200, $500 |
| Moroccan dirham | All | |
| Namibian dollar | All | |
| Netherlands Antillean gulden | 10, 25, 50, 100 gulden | 250 gulden |
| Norwegian krone | All | |
| Polish złoty | 10, 20, 50, 100 złotych, 200 złotych, 500 złotych | All |
| Romanian leu | All, Commemorative 2000 lei, All, All, 100 lei , 100 lei | |
| Saudi riyal | All | |
| Singapore dollar | All, S$10 and S$50 | |
| South African rand | All | All |
| South Korean won | All | |
| Slovak koruna | SKK 200, SKK 500, SKK 1000, SKK 5000 | SKK 100, SKK 50, SKK 20 |
| Sudanese pound | 50 Sudanese pounds, 100 Sudanese pounds, 500 Sudanese pounds | 1, 2, 5, 10, 20 and 50 Sudanese pounds |
| Surinamese dollar | 50 and 100 | 5, 10, 20 |
| Swazi lilangeni | All, 100 and 200 emalangeni | |
| Swedish krona | All | 20 kr, 50 kr, 100 kr, 500 kr, 1000 kr |
| Swiss franc | All | |
| Thai baht | ฿20, ฿50, ฿70, ฿100, ฿500, ฿1000, All, All | ฿20, ฿50, ฿100, ฿500, ฿1000 |
| Tunisian dinar | 10 dinars, 5 dinars, 50 dinars, 10 dinars, 5 dinars, 20 dinars | 5, 20, and commemorative 30 dinars |
| Turkish lira | 20,000,000 TL, 2005 and 2009 series | |
| Ugandan shilling | All | |
| United Arab Emirates dirham | 500 dirhams, 50 dirhams | 5, 10, 20, 50, 100, 200, 1000 dirhams |
| United States dollar | $5, $10, $20, $50, $100 | $1, $2, $100 |
| Zimbabwean bond notes | $2, $5 |