Ever since then, hundreds of academic papers have been published to improve the efficiency and security of e-cash constructions - to name a few.
从那时起，已发表了数以百计的学术论文试图改善例如电子货币构造的效率和安全的问题。
2
To prevent e-cash from double-spending and unlimited increase in the records of databases, an improved offline e-cash system based on elliptic curve cryptography was proposed.