The Proposed Protocol Sample Clauses

The Proposed Protocol. The proposed protocol Malicious Agreement Protocol (MAP) can solve the BA problem due to faulty sensor nodes which may send wrong messages to influence the system to reach agreement in a synchronous CWSN. MAP protocol consists two phases and needs σ rounds of message exchange to solve the BA problem.

The Proposed Protocol. In this section, we describe a one round authenticated group key agreement protocol which uses one more key pair as well as the long term public and private keys of typical IBE system. 5.1 System Setup [Verification] Each user  verifies  and  as fol- lows:                  If the above equation holds, then  accepts  as the message from  . [Key Computation] Upon receiving        from other users, each user  computes the session key as follows:    [Setup]                              The KGC generates the following system                  parameters:   {            } The KGC selects an elliptic curve  de- fined over  with order  and a base point . And then, chooses a master key               VI. Analysis ∈  and computes  by    and 6.1. Security    publishes system parameters. [Extract] A user  (1 ≤ i ≤ n) picks a random in- Key Authentication: This property re- quires that only users of the group are al- lowed to know the key. In our protocol, the only user to have the long term private keys  and  can deliver messages to other users owing to the signature verification process. If an adversary doesn't know  and a ephemeral key , he can't compute the session key. According to the discrete logarithm hardness, the adversary cannot extract  from    and cannot com-  nation when the compromise of one user's long term private key does not imply that the private keys of other users will also be compromised. Suppose that an adversary who knows the user  's long term private keys  and  wishes to impersonate the user  to all other users. He chooses an ephemeral key  ′ and computes  ′   ′ (1≤ ≤n,≠j), but he can’t compute        ′    ′    without the user  's pute       ≠     .        Forward Secrecy: This property requires that disclosure of long term secret of a user does not compromise the previous session keys. Though the private keys  and  of  are disclosed, the adversary cannot ex- tract  from    and he cannot com- long term private keys  and . Therefore, the adversary may impersonate the compro- mised user in the subsequent protocols, but cannot impersonate other users. Known Session Key ...

The Proposed Protocol. In this section, we shall introduce the proposed protocols RC and UAP to solve the BA problem with dual failure mode for the processors in a UNet. In UAP, RC is used to find out the c node-disjoint paths by the graphic information [3] to receive the messages from the sender processor, and the number of rounds of UAP operations is t +1 (t = ⎣(n-1)/3⎦). RC can provide a reliable channel to help the processors to transmit messages to each other, and using RC can make an un-fully connected network act just like a fully connected network without the common knowledge of the graphic information of the whole network structure. Moreover, the protocol RC encodes a transmitted message by using Manchester code before transmission. Therefore, the message(s) from dormant faulty processor can be detected by healthy processor. The definition of the protocol RC is shown in Figure 3. In a UNet, each processor only has the partial knowledge of its own graphic information. For example, in Figure 4(a ) and 4(b), P1 and P3 only have the information of the connection state of itself. Therefore, it is impossible for P1 to transmit a message to P3, and the reason is that P1 does not know the location of P3. In this study, the proposed RC can enable a sender processor to transmit a message to the destination processor without the location information of the destination processor. UAP can tolerate fm malicious faulty processors and fd dormant faulty processors, where n>⎣ (n-1)/3⎦+2fm+fd and c>2fm+fd. The definition of protocol UAP is shown in Figure 5. There are two phases in protocol UAP, which are the message exchange phase and the decision making phase. In the message exchange phase, each processor exchanges messages with others to get enough information through RC, which needs t +1 rounds of message exchange. If the received message is through the dormant faulty processors, then replace the value λ0 as the received message, if the received message is λi, then replace the value λi+1 as the received message (The value λi is used to report the absent value , where 0≦ i ≦t –1). In the protocol RC, the sender processor Pi (1≤ i ≤ n ) will transmit the value vi to the destination processor Pj (1≤ j ≤ n ) directly (if the sender processor has the connection with the destination processor). Moreover, the sender processor Pi will also transmit the value vi through the processor Py (1≤ y ≤ n ) which has connection with the sender processor Pi, then each intermediate processor Py (except t...

The Proposed Protocol. The proposed protocol Optimal Malicious Agreement Protocol (OMAP) can solve the BA problem due to faulty sensor nodes which may send wrong messages to influence the system to reach agreement in a synchronous CWSN. OMAP protocol consists two phases and needs σ rounds of message exchange to solve the BA problem.

The Proposed Protocol. In this paper, a new protocol, the Generalized Byzantine Agreement Protocol (GBAP) is proposed to solve the BA problem due to faulty component(s), which may send incorrect messages to influence the system to reach agreement in the virtual subnet. The notations and assumptions of the GBAP protocol for the virtual subnet network are shown below: ■ Let Pm be the total number of malicious faulty processors in a group. ■ Let Pd be the total number of dormant faulty processors in a group. ■ Let Cm be the total number of malicious faulty communication media in the virtual channels. ■ Let Cd be the total number of dormant faulty communication media in the virtual channels. ■ Let PGm be the maximum number of malicious faulty groups allowed. ■ Let PGd be the maximum number of dormant faulty groups allowed. ■ Let CGm be the maximum number of malicious faulty virtual channels allowed. ■ Let CGd be the maximum number of dormant faulty virtual channels allowed. ■ Let TFP is the total number of allowable faulty processors, TFP= Pm + Pd. ■ Let TFC is the total number of allowable faulty virtual channels, TFC= Cm + Cd. ■ Let ν is the number of processors in a group. ■ Let γ is the number of communication media in the virtual channel. ■ Let g be the group identifier where g>(g–1)/3+2(PGm+CGm)+PGd+CGd. ■ Let c be the connectivity of the virtual subnet network, where c is g–1 and c>2(PGm+CGm)+PGd+CGd. ■ Each processor can leave from the network or migrate into the network before executing GBAP. ■ In the BA problem, the source processor can transmit messages in the first round of message exchange phase. ■ Each processor always knows the total number of processors in the network. ■ The messages have encoded by Manchester code before communication [6]. Hence, the dormant faulty components can be detected. The procedure TRANSMISSION used to transmit messages in GBAP is based on the virtual subnet network characteristics [2] TRANSMISSION can provide a virtual channel to help each processor to transmit messages to each other. A detailed description of our proposed protocol based on the procedure TRANSMISSION is shown in Figure 2. Procedure TRANSMISSION Step 1: The sender processor Pi (1≤i≤n) transmits the value vi to the receiver group. Step 2: If the group-disjoint path from sender processor to destination group passes through any dormant faulty processor or if the sender processor has dormant faults, then stores λ0 itself. Step 3: The processors in the receiver group take the l...

The Proposed Protocol. 4.1. Dual semirings action 1. ▇▇▇▇▇ chooses as a secret key two reduced polynomials (for a polynomial in

The Proposed Protocol. This study proposes a new protocol TAP to solve the agreement problem of faulty TMs may send wrong messages to influence the system to achieve agreement in a CMCC. The proposed protocol TAP consists two phases, the message exchange phase and decision making phase. Moreover, TAP only needs two rounds of message exchanges to solve the agreement problem. In the first round of the message exchange phase, the source node ns multicasts its initial value vs through TMs by TTCB. And then, each node stores the received value in root of message-gathering tree (mg-tree) [9]. The mg-tree is a tree structure which is used to store the received messages. In the second round, each node ni acts as the sender, sending the value vs (received from source node ns) to other nodes by TTCB. However, the receiver can always detect the message(s) through dormant faulty components if the protocol TAP appropriately encodes a transmitted message by using Manchester code [7]. Hence, if the messages pass through any dormant faulty TMs, then λ will be stored in mg-tree of receiver. In decision making phase, in order to reduce the influence from the faulty components, a majority value is taken from all nodes in same cluster to set the majority value at level 2, Finally, the agreement among all nodes will be achieved. The proposed protocol TAP is presented in Figure 3. TAP protocol (for node ns with initial value vs) Message Exchange Phase Round 1: The source node sends its value (vs) to other nodes by TTCB; each receiver node obtains the value and stores the received value in the root of its mg-tree. If the cluster-disjoint path from source node to destination cluster passes through any dormant faulty transmission media, then λ is stored. Round 2: Each node transmits the values at the root in its mg-tree to each cluster’s nodes by TTCB. If the cluster-disjoint path from source node to destination cluster passes through any dormant faulty transmission media, then λ is stored. Each receiver node takes a majority on its received messages and stores the majority value in the corresponding vertices at level 2 of its mg-tree. Step 1: (1) Take the majority value of Vi in mg-tree.

The Proposed Protocol. The proposed solution has to satisfy the desired properties and avoid the unwanted ones. Thus, the proposed solution is a complete protocol that provides a mechanism to mitigate replaying attack, provides an encryption mechanism, enables anonymous connection, and provides mutual authentication process. The protocol has the following properties: 1. Has markers in each session in the form of session keys (each host has one session key with length up to 280 bits). 2. The session keys are generated by XOR computation of four random numbers (70 hex per random number). The session keys are used by both users to differentiate the messages in different sessions. 3. Has a mechanism to ensure that the random numbers that are received at the receiver side are correct. This mechanism is needed for both hosts to create the same session key. This is achieved by checking the MAC in each host. The MAC value that is sent by User B has the random numbers that is generated by User A and has been received by User B. If User A finds the difference in the MAC value (e.g., someone is altering the random numbers, or there is an error in the network so that User B cannot obtain the random numbers from User A), then User A will terminate the session. PIDA , PuB[▇▇▇, nA1, nA2] PIDB, PuA[IDB, nB1, nB2], MACB To be continued ….

The Proposed Protocol. This section formally presents the proposed protocol based on the model developed in Section 2. Based on the definition of an AIC problem, every processor has its own initial value to perform the protocol to reach an interactive consistency. Based on the results of ▇▇▇, ▇▇▇▇, ▇▇▇▇ (▇▇▇ et al., 1999), within two rounds of message exchanges, all fault-free processors can reach an agreement for all fault-free processors as if d dormant faulty links and m malicious faulty links exist in a n-processor fully connected network, in which m ≤ (n-d-3)/2. With a similar procedure, each processor performs the third round of message exchange. The proposed protocol can make all fault-free processors reach an agreement on the values they received in the first round. All fault-free processors can reach an agreement on common faults caused in the first round by comparing the common values received before and after the first round of message exchanges. Based on the same idea, the protocol can make all fault-free processors reach an agreement on a common set of faulty components if the components explore their faulty behavior in the second round of message exchanges. Therefore, all faulty components are detected and located by all fault-free processors and an interactive consistency is reached. The FDA problem is solved. Figure 1 illustrates the PFDA protocol, which can make all fault-free processors tolerate/detect/locate a common set of d dormant faulty links and m malicious faulty links which simultaneously exist in a n-processor fully connected network, where m ≤ (n-d-3)/2. PFDA reaches interactive consistency using two rounds of message exchanges and detects/locates a common list of faulty components using two additional rounds of message exchanges. We will demonstrate 1) the proposed method’s efficiency, and 2) the necessary and sufficient conditions for the number of rounds deemed necessary and faulty components allowed by PFDA. Protocol PFDA (For processor i with initial value vi,1≤ i ≤ n)