OBJECTIVES This study investigated whether coins of the new European currency (euro) corrode when they are exposed to gastric acid, and whether this change can be detected radiographically. METHODS The eight different denominations of coins were immersed for seven days in 0.15 N hydrochloride acid (HCl), which corresponds to the level of post-prandial gastric acid. A Swedish crown coin and th...

Since the release date struck on a coin is important information of its monetary type, recognition of extracted digits may assist in identification of monetary types. However, digit images extracted from coins are challenging for conventional optical character recognition methods because the foreground of such digits has very often the same color as their background. In addition, other noises, ...

Electronic cash is one of the most important applications of public-key cryptosystems. This paper gives lower bounds for data size and computational complexity of divisible electronic cash based on the Chaum-Fiat-Naor (CFN) paradigm, with respect to the precision of divisibility, N , which is (the total coin value)/(minimum divisible denomination). Achieving computational lower bounds in the mo...