International Journal of Network Security
In 2013, the researchers proposed an untraceable online electronic cash scheme from the RSA cryptosystem. They used a method that injects the expiration date and the spender's identity onto the coin to prevent double spending. The authors claimed that the scheme provides the properties of anonymity, unforgeability and double spending detection and date attachability. Unfortunately, the authors find that there are security flaws in terms of verifiability, unreuseablity and unforgeability. First, the verifiable method of e-cash in their scheme is not correct according to Euler's theorem.