Efficient password authenticated key agreement using smart cards

1
Efficient password authenticated key agreement
using smart cards

• Author Wen-Shenq Juang
• Source Computers and Security, vol. 23, pp.
  167-173, 2004.
• Speaker Jung-San Lee
• Date 2004/10/06

2
Notations

• x the secret key of the server S
• Ek(m) the encryption of the message m with the
  encryption key k
• Dk(m) the decryption of the message m with the
  decryption key k
• h() a public one-way hash function
• ru, rs two random numbers
• N1, N2 two nonce
• sk the negotiated session key

3
The Proposed Scheme

• Registration Phase
• Login and session key agreement phase

4
Registration phase
OK
User Ui
Server S
IDi, PWi
Vi h(IDi, x), Wi Vi ? PWi
Smart card IDi, Wi
5
Login and key agreement phase
IDi, PWi
User Ui
Server S
Vi Wi ? PWi
Vi h(IDi, x)
OK
Computes h(IDi N1)
sk h(ru, rs, Vi)
Dsk(Esk(N21))
6
Conclusions

• Simple
• Efficient