Cryptanalysis and enhancements of delegation-based authentication protocol for secure roaming service

摘要

Most recently, Youn and Lim proposed an improved delegation-based authentication protocol for secure roaming service with unlinkability. In this letter, we show that 1 it is vulnerable to a denial of service (DoS) attack 2 can not provide the unlinkability as claimed. Finally, we propose an enhanced protocol to remedy the security loopholes existing in it. Moreover, our improved protocol is still efficient.