The document proposes an Expedite Message Authentication Protocol (EMAP) for vehicular ad hoc networks that replaces the time-consuming process of checking certificate revocation lists with a more efficient revocation checking process using keyed hash message authentication codes. EMAP also uses a novel probabilistic key distribution method that allows non-revoked vehicles to securely share and update a secret key. Analysis shows that EMAP can significantly reduce message loss compared to conventional authentication methods using certificate revocation lists while providing security.

1. IEEE TRANSACTIONS ON MOBILE COMPUTING, VOL. 12, NO. 1, JANUARY 2014
EMAP: Expedite Message Authentication
Protocol for Vehicular Ad Hoc Networks

2. Abstract
 Vehicular ad hoc networks (VANETs) adopt the Public Key
Infrastructure (PKI) and Certificate Revocation Lists (CRLs) for
their security. In any PKI system, the authentication of a received
message is performed by checking if the certificate of the sender is
included in the current CRL, and verifying the authenticity of the
certificate and signature of the sender. In this paper, we propose an
Expedite Message Authentication Protocol (EMAP) for VANETs,
which replaces the time-consuming CRL checking process by an
efficient revocation checking process. The revocation check
process in EMAP uses a keyed Hash Message Authentication Code
ðHMACÞ, where the key used in calculating theHMAC is shared
only between nonrevoked On-Board Units (OBUs). In addition,
EMAP uses a novel probabilistic key distribution, which enables
nonrevoked OBUs to securely share and update a secret key. EMAP
can significantly decrease the message loss ratio due to the
message verification delay compared with the conventional
authentication methods employing CRL. By conducting security
analysis and performance evaluation, EMAP is demonstrated to be
secure and efficient.

3. Existing System
 Existing system focused on the problem of collusion in distance
bounding, in which two dishonest verifiers pool information to
make one of the verifiers look closer by sending similar kind of
signals.
 A verifier could then request to have a key distributed to it and
the prover, which the prover could then use to authenticate its
authenticated response.
 Existing methodology involves the
 Validation of the request by key exchanges and remedial measures
in checking the genuinity of the message. – if the data is not proper
reject the message which indicates genuinity is a notable problem.
 Validating the users data origin in turn checking out the MAC
data of the user requests raised. – arising from other machine
indicates the genuinity of request origin.
 Verifying the turn around time taken for processing the request.
inappropriate duration indicates an issue at the prover side

4. Proposed System
 Proposed system holds the existing processing model with an
enhanced ciphering algorithm to make the system more robust.
 Although, the researchers are interested in authentication
enhanced system. We are utilizing some of the concepts
introduced in the secrecy logic for authenticating the users. This
involves the logic to show what a verifier can conclude from
interacting with an honest prover.A timing based input
information followed by consecutive timing measurement
provides more optimistic approach in authenticating the user.
 Our proposed system provides a proof breaks down concept if
the prover is dishonest.
 Validate the authentication information provided by the user.
 Extract the MAC address to validate the request origin location.
 Consecutive Execution time duration on the request processing

5. System Requirements
 Hardware Requirements:
Processor : Core 2 duo
Speed : 2.2GHZ
RAM : 2GB
Hard Disk : 160GB
 Software Requirements:
Platform : DOTNET (VS2010) , ASP.NET
Dotnet framework 4.0
Database : SQL Server 2008 R2

6. Architecture Diagram