hoc Networks (VANETs) consists of vehicles and distributed roadside units
(RSUs). The vehicles can send safety related messages like speed, location of
the vehicle, dangerous road conditions to any nearby vehicles and to the RSU
and vice versa. In VANET, each vehicle broadcasts a message to nearby vehicles
and RSUs every few hundreds of milliseconds. A vehicle or an RSU may receive
hundreds of messages in a short period. If the messages cannot be processed in
time, occurrence of traffic jams and accidents is possible. Hence, it is
critical to devise security and privacy mechanisms that never lead to an
unaffordable reaction delay. As the wireless communication channel is a shared
medium, exchanging messages without any security protection over the air can
easily leak the information that users may want to keep private. Pseudonym
based schemes have been proposed to preserve the location privacy of vehicles.
However, those schemes require the vehicles to store a large number of
pseudonyms and certifications, and do not support some important secure
functionality such as authentication and integrity. Existing secure and privacy
preserving protocols in VANETs are fast and does not depend on ideal tamper
proof devices embedded in the vehicles. This is a major concern when it comes
Existing secure and privacy-preserving vehicular communication
protocols in vehicular ad hoc networks face the
challenges of being fast and not depending on ideal tamper-proof
devices (TPDs) embedded in vehicles. To address these challenges,
propose a vehicular authentication protocol referred to as distributed aggregate privacy-preserving authentication. The pro- posed protocol is based on our new multiple trusted
authority one-time identity-based aggregate signature technique.
technique a vehicle can verify many messages simultaneously and their signatures can be compressed into a single one that greatly reduces the storage
space needed by a vehicle or a data collector (e.g., the traffic management authority). Instead of ideal TPDs, our
protocol only requires realistic TPDs and hence is more practical.
In VANET some serious network attacks such as man in
middle attack, masquerading is possible. Vehicle privacy is also a critical
concern. A vehicular message usually contains information on a vehicle’s speed,
location, direction etc. From those messages, a lot of private information
about the driver can be inferred. Furthermore, malicious vehicles may send fake
messages to misguide other vehicles into accidents. This implies that privacy
should be conditional in the sense that the message generators should be
traceable when fake messages cause harms. For this purpose, the
vehicle-generated messages must be stored by the receiving vehicles and other
entities (e.g., the traffic management authority). In VANET, each vehicle
broadcasts a message to nearby vehicles and RSUs every few hundreds of
milliseconds. A vehicle or an RSU may receive hundreds of messages in a short
period. If the messages cannot be processed in time, traffic jams and even
accidents may ensue.
Hence, it is critical to devise
security and privacy mechanisms that do not lead to an unaffordable reaction
delay. Existing secure and
privacy-preserving vehicular communication protocols in vehicular ad hoc
networks face the challenges of being fast and not depending on ideal
tamper-proof devices (TPDs) embedded in vehicles. The proposed protocol is based on a new multiple
trusted authority one-time identity based, frequency and attribute – based
aggregate signature technique. A vehicle is able to verify many messages at the
same time and their signatures can be compressed as a single unit. This reduces
the storage space required by a vehicle or a data collector to a considerable
extend. A practical cooperative message authentication protocol is
proposed to elevate the verification burden, where each vehicle just needs to
verify a small amount of messages. The details of possible attacks and the
corresponding solutions are also discussed.
Vehicular ad hoc networks (VANETs)
are created by applying the principles of mobile ad hoc networks (MANETs) – the
spontaneous creation of a wireless network for data exchange – to the domain of
vehicles. VANETs were first mentioned and introduced in 2001 under
“car-to-car ad hoc mobile communication and networking” applications,
where networks can be formed and information can be relayed among cars. It was
shown that vehicle-to-vehicle and vehicle-to-roadside communications
architectures will co-exist in VANETs to provide road safety, navigation and
other roadside services. VANETs are a key part of the intelligent
transportation systems (ITS) framework.
are referred as Intelligent Transportation Networks. VANET became mostly
synonymous with the more generic term Inter-Vehicle
although the focus remains on the aspect of spontaneous networking, much less
on the use of infrastructure like Road Side Units (RSUs) or cellular networks.
VANETs can use any wireless networking technology as their basis. The most
prominent are short range radio technologies like WLAN (either standard Wi-Fi
or ZigBee. In addition, cellular technologies or LTE can be used for VANETs.
The latest technology for this wireless networking is visible light
VANETs support a wide range of
applications – from simple one hop information dissemination of, e.g.,
cooperative awareness messages (CAMs) to multi-hop dissemination of messages
over vast distances. Most of the concerns of interest to mobile ad hoc networks
(MANETs) are of interest in VANETs, but the details differ. Rather than moving
at random, vehicles tend to move in an organized fashion. The interactions with
roadside equipment can likewise be characterized fairly accurately. And
finally, most vehicles are restricted in their range of motion, for example by
being constrained to follow a paved highway. The various applications of VANETS
are listed below.
applications include monitoring of the surrounding road, approaching vehicles,
surface of the road, road curves etc. The Road safety applications can be
ü Real-time traffic: The real time traffic data can be stored at the RSU
and can be available to the vehicles whenever and wherever needed. This can
play an important role in solving the problems such as traffic jams, avoid
congestions and in emergency alerts such as accidents etc.
ü Co-operative Message Transfer: Slow/Stopped Vehicle will exchange
messages and co-operate to help other vehicles. Though reliability and latency
would be of major concern, it may automate things like emergency braking to
avoid potential accidents. Similarly, emergency electronic brake-light may be
ü Post Crash Notification: A vehicle involved in an accident would
broadcast warning messages about its position to trailing vehicles so that it
can take decision with time in hand as well as to the highway patrol for tow
ü Road Hazard Control Notification: Cars notifying other cars about road
having landslide or information regarding road feature notification due to road
curve, sudden downhill etc.
ü Cooperative Collision Warning: Alerts two drivers potentially under
crash route so that they can mend their ways.
applications will provide the driver with the entertainment and services as web
access, streaming audio and video. The Commercial applications can be
ü Remote Vehicle Personalization/ Diagnostics: It helps in
downloading of personalized vehicle settings or uploading of vehicle
diagnostics from/to infrastructure.
ü Internet Access: Vehicles
can access internet through RSU if RSU is working as a router.
Digital map downloading: Map of
regions can be downloaded by the drivers as per the requirement before
traveling to a new area for travel guidance. Also, Content Map Database
Download acts as a portal for getting valuable information from mobile hot
spots or home stations.
Real Time Video Relay: On-demand
movie experience will not be confined to the constraints of the home and the
driver can ask for real time video relay of his favorite movies.
ü Value-added advertisement: This is especially for the service
providers, who want to attract customers to their stores. Announcements like
petrol pumps, highways restaurants to announce their services to the drivers
within communication range. This application can be available even in the
absence of the Internet.
Convenience application mainly
deals in traffic management with a goal to enhance traffic efficiency by
boosting the degree of convenience for drivers. The Convenience applications
can be classified as:
ü Route Diversions: Route and trip planning can be made in case of road
ü Electronic Toll Collection:
Payment of the toll can be done
electronically through a .Toll Collection Point. A Toll collection Point shall
be able to read the OBU of the vehicle. OBUs work via GPS and the on-board
odometer or techograph as a back-up to determine how far the Lorries have
travelled by reference to a digital map and GSM to authorize the payment of the
toll via a wireless link. TOLL application is beneficial not only to drivers
but also to toll operators.
The Productive applications can be
Environmental Benefits: AERIS
research program is to generate and acquire environmentally-relevant real-time
transportation data, and use these data to create actionable information that
support and facilitate “green” transportation choices by transportation system
users and operators.
ad hoc network (VANET ), consisting of a network of vehicles, moving at a
relatively high speed, that communicate among themselves with different
purposes, being the main purpose that of improving security on the road. In
VANET, each vehicle broadcasts a message to nearby vehicles and RSUs every few
hundreds of milliseconds. A vehicle or an RSU may receive hundreds of messages
in a short period. If the messages cannot be processed in time, occurrence of
traffic jams and accidents is possible. Five categories of proposals have
addressed security and privacy concerns in VANETs. The first category is based
on digital signatures combined with anonymous certificates. To cope with the
privacy issue, digital signatures must be combined with short-lived anonymous
certificates. The second category is based on group signatures. This approach
is free from traditional certificate management.
third category is based on identity-based cryptography (IBC). In IBC, an entity
uses a recognizable identity as its public key and its private key is generated
by a trusted authority (TA) using a master secret. To achieve privacy, the
identity of an entity is replaced with pseudonyms. This approach is similar to
the one based o25n anonymous certificates.
The fourth category is about the IBV protocol which is based on an ideal tamper-proof device (TPD)
ü Suffers from a
heavy certificate management burden to maintain all the anonymous certificates
of all the vehicles.
ü The verification
and transmission costs of a group signature are very much higher than those of
a traditional signature.
ü The overheads of
signature verification and transmission are very high.
ü Experiences the
problem of pseudonym burden.
new multiple trusted authority one – time identity based protocol is proposed
to solve the mentioned disadvantages in the existing system. This protocol is
based on frequency and attribute – based aggregate concept. A vehicle in the
VANET is able to verify many messages at the same time and all their signatures
can be compressed as a single unit. This paves way to reduce the storage space
required by a vehicle or a data collector to some extent. A co – operative
message authentication protocol is proposed to elevate the verification burden
where each vehicle needs to verify a small amount of messages. This protocol
consists of a root TA, several lower-level TAs and users. Each lower-level TA
is enrolled by the root TA. A user can register to any lower-level TA and
compute a signature on a message if the user has obtained a private key from
the lower-level TA. The signature is only valid under the user’s identity and
the public information of the lower-level TA. This protocol is resistant to
side – channel attacks. The possibility
of various attacks and their corresponding solutions are discussed. Also
developed a system analytical model for analyzing various information about the
traffic conditions and carry out NS2 simulations to examine the key
distribution delay and missed detection ratio of malicious messages, with the
proposed key management framework. Instead
of ideal TPDs, this protocol only requires realistic TPDs and hence is more
Attribute based encryption scheme is used in this
Handle large number of messages
Signature based SHA algorithm
Proposed a Multi Trusted Authority One Time Frequency
Attribute based Aggregate Signature Scheme (MTA-OTFABAS), a protocol for
secure vehicular communications. This protocol is based on frequency and
attribute based aggregate concept.
MTA-OTFABAS achieves enhanced privacy (i.e., conditional unlink
ability), key escrow freeness, robustness and fast message processing, without
requiring an ideal TPD. Simulations show that our protocol is practical.