抄録
Road safety and traffic efficiency are two important applications of a
Vehicular Ad-hoc Network (VANET). In VANET, safety and emergency messages are
broadcasted to all vehicles in a risk zone before the validity of the message expires.
Emergency and safety-related communications have a very strict real-time requirement
of 100ms latency from an originating host’s application layer to destination host’s
application layer and a Packet Delivery Ratio (PDR) of 90% and above. Due to
one-to-many nature of these emergency messages, public-key encryptions may not be
employed. Furthermore, vehicles on the road have no constant access to the Roadside
infrastructure. Thus, access to a Public-key Infrastructure or a Certificate Authority is
not always guaranteed. Exploiting this weakness, any attacker with malicious intention
can broadcast falsified emergency messages with spoofed identity to disrupt the normal
operation. They may also do in order to launch a terror-like attack. Since the identity
of the originating malicious vehicle cannot be established, it is not possible to take any
legal action against the owner of these vehicles.
In this paper, we propose a smart digital certificate mechanism using a modified
threshold cryptography scheme, that we call it as a pseudo-identity based encryption
to identify the origin of every emergency message. Since the keys are not forgeable,
any such malicious activities are immediately known to the receiving host vehicles
and vehicle registration authorities, thus facilitating legal action. The main advantage
of our proposed scheme is that it can work without constant access to a Public-key
Infrastructure or a Certificate Authority. Our scheme satisfies the identical security
requirements as that of the underlying public-key cryptography and incurs the same
memory and run-time complexity.
The proposed scheme can also be implemented in a Mobile Ad hoc environment
or a distributed environment, where source authentication is an important factor, and
there is no constant access to the backbone of the network.
