Kim, MinhoKoç, Çetin Kaya2020-11-212020-11-2120071816353Xhttps://hdl.handle.net/11467/4042Rivest and Shamir presented two simple micropayment schemes, "PayWord" and "MicroMint," for making small purchases over the Internet [14]. Recently, Adachi et al. have pointed out that the PayWord scheme has two security problems, and proposed a new micropayment scheme to overcome these problems [1]. Nevertheless, we show that their protocol is still vulnerable to impersonation and replay attacks.eninfo:eu-repo/semantics/closedAccessElectronic commerceImpersonationMicropaymentPaywordReplay attackArticle42235239N/A2-s2.0-77951135883