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- The secret codes of British banknotes http://www.bbc.com/future/story/20150624-the-secret-codes-of-british-banknotes 61 comments
- Watermarks invisible to humans prevent image editing programmes from reading banknotes, not the visible constellations that photocopiers detect http://www.bbc.com/future/story/20150624-the-secret-codes-of-british-banknotes 16 comments programming
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