Table 1 Notations in this study
From: Secure protocols for data propagation and group communication in vehicular networks
Notations | Descriptions |
|---|---|
E(Msgs, K) | The messages (Msgs) are encrypted by the key, K |
R i or RSU i | The identity of a fixed station on the roadside |
TPmap | A travel route, tp, in the Google MAP |
PK/SK | An asymmetric key pair, issued by the trusted third party |
K i, j | A secret key between v i and v j |
k/k P | A key pair, private/public keys in the Elliptic Curve Cryptography |
VGK | A virtual group key among the vehicles in a V2I virtual group |
GGK | A global group key among the vehicles in a V2V global group |
GKset, GKsetP | A ECDH-based key pair, generated by the trusted third party at a time, Tstamp, for a set of RSUs, {R j }, on the route (tp) to service the vehicles, {v i }, when they travel during the required trip period, ΔT. (i.e. set = hash(tp||ΔT||{R j }||{vi}||Tstamp)) |
Cert vi | The certificate with a valid public key of v i , issued by the trusted third party |
GPS vi | The GPS position (x, y) of v i |
v i or V i | The identity of vehicle i |
Event k | An event type of traffic-related information |
TH | A head vehicle in a one-hop physical group, moving with a steady velocity (or approximately steady velocity) |
NList x | The latest identities of neighboring vehicles of Vehicle x |
gk x | A group key, shared between all members and their head, x, in a physical group |
Sign(Msg, SK) | The digital signature of Msg, signed by the private key, SK |
MAC(Msg, K) | The MAC code of Msg, encrypted with the secret key, K |
v limit | The maximum speed limit on the roadway |
R T | The standard transmission range of a vehicle |
Δdpj s→R | The projection distance from Sender(S) to Receiver (R) over the vector from the preceding sender of Sender |
Δt p | The delay time for the propagation of traffic-related information, defined in Equation (1) |
Δt A | The delay time for the role announcement of a TH, defined in Equation (2) |
ΔT | The trip period required by groups of friends, when they travel together |
Warn# | A warn message for the propagation of the traffic-related information |
Req# | A request message for that a vehicle applies for a virtual group |
Resp# | The response message corresponding to the Req# |
Req@ | A request message for that one TH tells its members to start the group key agreement process |
Notify# | A notification message from a RSU to the vehicles contains the information, "the RSU set is ready for your trip" |
"||" | The meaning of "join" |