Replay Attack. In order to resist the replay attack, our protocol uses short-term keys. The lifetime of the short-term keys kAi and kBi (i 1, 2, . . .) is only one session long, with a view of establishing (n2 + n) keys. The two parties have to randomly choose new short-term keys again in the next session. If the intruder attempts to replay the previously intercepted message to Xxx for masquerading as Xxxxx, Xxx will find out and reject this message.
Replay Attack. During the communication between the B-GKAP entities, an attacker might sniff mes- sages in the network and re-transmit sniffed messages for malicious reasons such as Denial of Service (DoS) attacks. To protect against replay attacks, timestamp variable (T ) is added into the protocol messages. Hence, the receiver entity can check T value against replay attack attempts.
Replay Attack. The proposed scheme is secure against the replay attack due to the changeable session keys: SK = SKA = SKB = e(QA, QB )K(XA+XB)xAxBP. The session key derived from the hash value of the temporary identities and the public keys. The temporary identity GUTI is changeable according to the user’s loca- tion area, and hence when the attacker replays with the previous security parameters, then the request will be re- jected because the users UE’s will know that this request is invalid.
Replay Attack. Definition 4.6. A replay attack is a form of network attack in which a valid data trans- mission is maliciously or fraudulently repeated or delayed.
Replay Attack. 1 1 1 The replay attack is one of the known attacks that the attacker attempt to interrupts the message and resends it in later time. Suppose an adversary V intercepts the authentication message <Di, Ci, Fi, Xi> from the legitimate user Xx, and tries to replay the request message at a later point of the time. The proposed scheme make of use the freshly generated timestamp T for login and authentication. In each communication message the fresh timestamp is send in plain text like <Di, Ci, Fi, Xi> as well as embedded in some secret message such as Fi = (idbi || pwbi || N1 || Ri || T1) it contains timestamps T1. Therefore, if adversary V replays the old message it will not pass the freshness test, and if V may sends new timestamp along with the old message, it will not pass the next verification test where the proposed scheme checks the embedded timestamp by |T * - T | ≤ ∆T. Figure 5 shows this operation, where if |T * - T1| > ∆T, it will be fails to generate shared session key between client and server. So that, the proposed scheme prevents the replay attack. See figure 5-1.
Replay Attack. An adversary cannot start a replay attack against our scheme because of the freshness of ri in each session. If Tri (x) has appeared before or the status shows in process, the participant Ui+1 rejects the session request. If the adversary wants to launch the replay attack successfully, it must compute and modify Tri (x) and Ci cor- rectly which is impossible.
Replay Attack. An attacker sends a message that the server has already accepted, aiming to deceive the server and successfully pass the authentication process. In cross-domain authen- tication, the attacker might intercept a message sent by a device in domain A and forward the message to domain B to achieve successful authentication.
Replay Attack. If the intruder can impersonate the source node or the destination node by replaying information what he or she collected as the source node and the destination node established a pairwise key, we say that the protocol used for security can not prevent the replay attack [10]. In TLPKA, the source node and the destination node record the random number di and nonce ci for a period of time. Even if the intruder can collect messages gdi , Ekij{x x} , Ekij{ci,x x' + 1} , and Ekij{ci' + 1} , he or she can not impersonate the source node or the destination node and try to establish a pairwise key with a normal source node or destination node. If the intruder tries to impersonate the destination node, the normal source node will check to see whether it can receive the correct challenge ci+1 and different ci in Step 11 of the Source Node part. The message of Step 11 changes each time. Only the source node can decrypt the correct challenge ci′+1 and check its validity. Consequently, the old message can not be used for a replay attack.
Replay Attack. In [12], Ȃ may initiate replay attack which may prevent user and ESP to authenticate the involved CSj. The attack may be initiated by taking the following steps:
Replay Attack. In the proposed scheme (BioKA-ASVN), all the communicated messages Msg1 = V3, V2, V1, TS1 , Msg2 = V1, TS1, , SKV1, T1, TS2 , Msg3 = Cert∗j , SKV2, T2, IDj∗, TS3 and Msg4 = T1′ , SKV2, T2, TS2, TS3, TS4 contain fresh timestamps. Therefore, once an older message is retransmitted, it can be easily detected by verifying the attached timestamp. Hence, BioKA-ASVN resists the replay attack under the DY threat model.
