Figure 11 shows the statistical results of the 100 simulations on the replay attack
. Although the replayed sensor data can avoid being detected by the CUSUM detector, it is more likely to induce an abnormal behavior in the controller's output.
Yang Yoon and Yoo scheme  scheme  (A1) Replay attack
() X (A2) Modification attack () () (A3) Stolen-verifier attack () () (A4) off-line guessing attack () X (A5) Forgery attack () X (A6) Insider attack X X (A7) Masquerade attack X X (A8) Smart card attack () X (A9) User impersonation attack () () (A10) DoS attack X X Attack resistance Chuang and Chen Our scheme scheme  (A1) Replay attack
() () (A2) Modification attack () () (A3) Stolen-verifier attack () () (A4) off-line guessing attack () () (A5) Forgery attack () () (A6) Insider attack () () (A7) Masquerade attack X () (A8) Smart card attack X () (A9) User impersonation attack X () (A10) DoS attack X () TABLE 3: Comparison of efficiency measures.
(1) Replay Attack
Resistance: It is difficult for the attackers to guess the value of the random number as the random numbers are newly created in each authentication procedure.
A replay attack
is a form of network attack in which a valid data transmission is maliciously or fraudulently repeated or delayed.
For defense against the replay attacks
in Attack Model 3, BECAN  adopts the timestamp technology.
(3) Resistance of replay attack
: it is impossible for CSPs to generate the proof matched with the challenge using the previous proofs ([T.sub.pre], [D.sub.pre]), without retrieving the actual cloud data m.
The security analysis proves that the SE-H protocol can defeat the existing attacks such as impersonate attack, tracking attack, desynchronization attack and replay attack
. Moreover, the performance analysis in terms of operations cost of authentication illustrates that the proposed protocol satisfies the highest level of security with lowest cost performance comparing with existing mutual authentication protocol for RFID systems.
The wireless channel is prone to attacks such as replay attack
, counterfeit attack, and tracking attack.
It is used for replay attack
prevention as well as session key generation.
A replay attack
is a breach of security in which data is stored without authorization and then retransmitted in order to trick the receiver into energy exhaust operations.
In addition, the tickets use the timestamp to prevent replay attack
, which means that the clock of clients and servers should be synchronized.
Additionally, we developed Merkle hash tree by making a user's query to work one-time which leads to prevent an adversary from applying his malicious attacks such as Man-in-the-Middle (MITM) attack, insider attack, and replay attack
. In addition, our proposed scheme provides many pivotal merits: more functions for security and effectiveness, mutual verification, key agreement, dynamic data support, recoverability when some data blocks are lost, unlimited number of queries, and privacy preserving.