Scheme Design Sample Clauses

Scheme Design. ‌ In the Global Initialization phase, TA will publish the global system parameters {p, P, ID(Ui), stampUi , F (p)} to the registrants Ui. During the User Node Registra- tion phase, each new user node needs to register with the trusted third party. Specifically, before a new user wants to join or initiate a session, it must apply to TA for a user ID and timestamp. In the node initialization phase, five users form a group, and the session key and personal ID(Ui) ID of user Ui in the group stampUi The timestamp generated by the user’s registration with TA F (p) Hash domain PKUi , SKUi Public and private key pair of user ▇▇ SignCA, V erCA signature and verification algorithm of CA {U1, U2, ..., Un} A list of users ri ∈ {1, N − 1}, where1 ≤ i ≤ 5 Security parameter, N is a field of prime numbers C(Ui) = (ID(Ui), V erUi , SignCA(ID(Ui)), V erUi )) The user’s public key certificate obtained from the CA SignUi , V erUi signature and verification algorithm of user ▇▇ Hash A one-way hash function:G → Zp sha − 256(CK(message)) yrn L Hash the encrypted message and spell the user’s own signature , concatenation symbol and XOR decryption key are negotiated and generated, correspond- ingly. When a new user joins or an old user leaves, the session key and personal decryption key of the group only need one round of communication to be updated. In the phase of Session Key Update, when there are fewer than five members in the communication group (if a user leaves, they will inform the TA, and the TA generates a times- tamp to record the insufficient number of group mem- bers), any registered user can apply to join the communi- cation. The communication order is based on the order of registration. Additionally, if one user is recommended by two or more users in the group, it does not need to queue and can enter the session with priority.

Scheme Design. ‌ To address the security and privacy issues of VANET group communication, this paper designs a secure and efficient group key agreement scheme for VANET in bilinear groups. The vehicles will apply for their own group when registering with the TA. TA will authenticate them and assign relevant group identification according to vehicle attribute. The RSU computes the group key for the vehicles in its coverage according to the group identification. When vehicles are driving in the same RSU coverage area, they with the same group identification initiate group key negotiation due to communication needs. With the relatively fixed location, wide coverage, strong communication and computing capabilities, the RSU is selected as the manager of the group to complete the signature batch authentication of the vehicles and compute and distribute the group key. This can greatly improve the negotiation efficiency of the group key and reduce the communication delay. Figure 2 depicts the process of our group key agreement. (1) TA initializes the system parameters and sends them to vehicles and RSUs. (2) The RSU requests registration to TA. (3) TA returns the verification information. (4) Vehicle sends the vehicle registration information to TA. (5) TA returns the verification information. (6) TA sends the partial vehicle verification information (the shared key, etc.) to RSUs. (7) Vehicle requests the group key agreement and sends its signature to the RSU. (8) The RSU sends the final group key agreement result to vehicle according to the signature verification. The scheme contains seven modules, i.e., parameter initialization, vehicle and RSU registration, vehicle signing, RSU verification, group key generation, group member joining, and group member leaving. TA ĸ RSU registration Ĺ RSU verification information ļ Vehicle verification information ķ Parameters Initialization ĺ Vehicle registration Ļ Vehicle verication information