1. 1 Further cryptanalysis of fingerprint-based remote user authentication scheme using smartcards Authors: W.C Ku, S.T. Chang,and M.H. Chiang Source: Electronics Letters, Vol. 41, No. 5, pp. 240- 241, 3 March 2005. Speaker: P. Y. Lin

2. 2 Password authentication schemes -password table -password table ID 格式是否正確 Input ID i ID 1 ID 2. ID n 12...n12...n 比較 PW i =  i ? password table 取出 PW i 是！接受通關 否！拒絕通關 是 否！拒絕 password table ID 1 ID 2. ID n PW 1 PW 2. PW n 使用者 名稱 通行碼

3. 3 Review of LRY scheme (1) Lee, Ryu and Yoo Registration phase user i server ID i PW i Smartcard: ( f ( ), p )

4. 4 Review of LRY scheme (2) Login phase  ＆ Authentication phase  user i server ID i, PW i, fingerprint i     check ID i and T  

5. 5 The forgery attack on LRY scheme Eva impersonates user i server Smartcard: ( f ( ), p )     yields PW i

6. 6 Cryptanalysis on LRY scheme forgery attack not easily repairable cannot choose and change users’ passwords