Security protocols

References

• Handbook of applied cryptography

! this book is not always up-to-date ! Some protocols might be broken today (eg. Needham-Schroeder public-key protocol)

Authentication Protocol

using public-key crypto - encrytion

Needham-Schroeder-Lowe protocol (NSL)

References: [1], hac, chap 12, §12.38

• Don't confuse with the symmetric variant (used in Kerberos).
• Orignal version (NS protocol) broken — use this variant instead.

A --> B: P_B(k_1,A)
A <== B: P_A(k_1,k_2,B)
A --> B: P_B(k_2)