Key Establishment. Xxxxx computes KE(gp, pB, sA) and Xxx computes KE(gp, pA, sB).
Key Establishment. For each 1 ≤ i, j ≤ k, Xxxxx computes zi,j = j(EBj/(Uj + [αi]Vj)), and then she calculates the hash h = H(z1,1, . . . , z1,k, z2,1, . . . , z2,k, . . . , xx,0, . . . , xx,x). Similarly, for each 1 ≤ i, j ≤ k, Xxx computes zij,j = j(EAi/(Ri + [βj]Si)), and calculates the xxxx xx = X(x0x ,0, . . . , x0x ,x, z2j ,0, . . . , x0x ,x, . . . , xxx ,0, . . . , xxx ,x). ≤ ≤
Key Establishment. Xxxxx computes zi,j ← KE(gp, pBi, sAj) for every pair 1 ≤ i, j ≤ k, then computes
Key Establishment. Key establishment may be broadly divided into key transport and key agreement. A key transport protocol or mechanism is a key establishment technique where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s). A key agreement protocol or mechanism is a key establishment technique in which a shared secret is derived by two (or more) parties as a function of information contributed by, or associated with, each of these, (ideally) such that no party can predetermine the resulting value. Thus in scenarios, where there is no central authority and the task of key generation cannot be assigned to a single (or few) participant(s)(as is most often the case in ad hoc networks), key agreement is a good alternative to key transport. But more often in a key agreement protocol, it is required that a participating member be assured that no other party aside from a specially identified party (or parties) may gain access to a particular secret key. Such a protocol is known as an authenticated key agreement protocol. It is worth noting here that the term authentication, in this context, means to have the knowledge of the identity of parties who may gain access to the key. To corroborate the fact that the same identities actually participated in the protocol, one has to rely on other mechanisms like entity authentication. Key agreement protocols can be designed using symmetric or asymmetric techniques. To further illustrate the above concepts present the two- party Xxxxxx-Xxxxxxx key agreement protocol.
Key Establishment. At this stage, the participants C3 m = e(di, C1) ∗ e(Q, C1) ∗ e(H(IDj)−1, C2) 4 Security Analysis
