S.S.: Secure Group Communications Using Key Graphs. In: SIGCOMM (1998) Improved approximation for the routing tree case when weights are uniform For the case where group members have the same key update probability and the communication network is a tree, (0)

by C K Wong, M G Gouda, Lam
Venue:in OPT(S) is ∆ more than the cost calculated in OPT(X). From Theorem 1, we know the increased cost is at least 3∆ · n log3 n = 3∆ log 3n log n. ⊓⊔ Theorem 6. This is a 4.2-approximation algorithm. Proof. ALG(S) ≤ ALG(X) + ALG(Y ) + 4∆ n log n + n (M(X) +