Every security system depends on trust, in one form or another, among users of
the system. In general, different forms of trust exist to address different types of problems
and mitigate risk in certain conditions. Which form of trust to apply in a given circumstance
is generally dictated by specified policy.The main design task is to discriminate between temporary errors and disguised malicious behaviours in which the attacker cleverly behaves well
and badly alternatively. Here describe a new trust management and redemption scheme that
can discriminate between temporary errors and disguised malicious behaviours. With help of a
sliding window the behaviour of nodes in a system can be well analyzed thus according to the
nature of behaviour the node can be categorized as normal or malicious.
The goals of the work are threefold. The first goal is that the source node detects
On-off attack nodes by employing a new type of trust and management scheme. The second
goal is that the badly reputed node would have a second opportunity for preventing the faulty
detections. The last goal is that we design an efficient and flexible scheme of the new management scheme. Trust management schemes aim to improve collaboration between the entities in
a distributed system by predicting future behaviors of peers based on their previous behaviors.
A trust management scheme typically does this using the following steps. First , Each node
observes and stores the neighbouring nodes behaviors. Second, each node collects and stores
the warnings or reports from other nodes about its neighbouring nodes. Third, each node calculates the trust based on the behavior information collected and stored for each neighbouring
node. Last, based on the trust and the policies that use the trust, each node decides the best
node or group of nodes with which to collaborate. Trust redemption schemes fail to discriminate between an On-off attack and temporary errors, if attackers behaviour is good. Scope of
the topic is to detect and prevent on-off attacks in various systems or working organization etc.
1.1 Motivation and Scope
Every security system depends on trust, in one form or another, among users of the system.
In general, different forms of trust exist to address different types of problems and mitigate risk
in certain conditions. Main scope includes below,
Jyothi Engineering College, Cheruthuruthy Dept. of CSE, May 2016
On-Off Attack Management Based on Trust 2
• Provide more secure environment
• Detection of malicious nodes
• Prevent on- off attack
• Better data transfer capability
Here present a new efficient and flexible trust management scheme that detects and defends against On-off attacks. Trust management framework relies on two key concepts-
• Predictability Trust
• Sliding Windows.
Predictability Trust works to detect On-off attacks.It uses sliding windows to keep track
of previous behaviours so that it can determine how quickly to redeem trust.
1.2 Application
Trust is applicable in every networking system and it always concern about providing
better trust and secure environment for the proper system flow. It has a wide applicability
which includes,
• High security applications
• Bank transactions
• industries
1.3 Challenges
Whenever the trust is considering related problems must be considered well in order to
provide a better system and a proper capabilities. But if the trust is not properly maintained,
the stability of the system is lost. If the system lacks the trust, many security issues may arrive
in system which lead to adverse effects. Main challenges are ,
• Proper calculation of trust
• Proper maintaining of trust
Jyothi Engineering College, Cheruthuruthy Dept. of CSE, May 2016
On-Off Attack Management Based on Trust 3
• Detection of On-Off attack
• Defend to On-Off attack
Trust redemption schemes fail to discriminate between an On-off attack and temporary
errors, if attackers behaviour is good. Scope and challenge of the system is to detect and prevent
on-off attacks in various systems or working organization etc.
Jyothi Engineering College, Cheruthuruthy Dept. of CSE, May 2016
On-Off Attack Management Based on Trust 4
CHAPTER 2
LITERATURE REVIEW
2.1 Trust Management Scheme
Trust Management Scheme define trust as the probability that an object performs a given
action as expected. A trust management scheme manages the trust by integrating the notions
of credentials, access control, security policy, availability, and authentication. By using the
integrated information, a trust management scheme can be used to aid an automated decisionmaking process for an access control policy. Trust can be evaluated in a variety of ways. Direct observation evaluates neighbouring nodes by observing their behavior. If a source node
compares the contents of the packets, it can detect fabrication or modification. With indirect
observation nodes publish their direct observations to their neighbouring nodes to warn about
malicious nodes or to report recovered nodes that were previously evaluated as malicious. Trust
evaluations can also be disrupted. When a node monitors the forwarding performance of its
neighbouring node, network fault may cause the packets to be lost on their way to the monitoring node even if the all of the packets were successfully delivered to the forwarding node. An
indirect observation can be disrupted by bad mouthing. An attack node may frame other normal
nodes to make them look like malicious nodes, or may recover the trust of a malicious node
by reporting false praises. To avoid faulty detections, direct observation can employ a trust
redemption scheme, and indirect evaluation minimizes the influences of the warning messages
or reports.
2.2 Trust Redemption Scheme
Because unintentional temporary errors may occur a redemption scheme is required to
allow an untrusted node to recover its trust value. Redemption schemes can be classified in two
ways. Behavior Based Redemption (BBR) recovers trust based on subsequent behaviors. Time
Based Redemption (TBR) recovers trust periodically. If both BBR and TBR are used together,
refer to this as Combined Redemption. In the following sections, here classify existing trust
models by these redemption schemes.
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On-Off Attack Management Based on Trust 5
2.2.1 Behavior Based Redemption
To understand Behavior Based Redemption, assume that a friend had a bad behavior in
the past, but since then the friend has behaved very well several times. Thus, can expect that
the friend will behave well in the next behavior. Similarly in a distributed system, if a node
behaves very well now, we can expect the node will behave well in the next behavior, even if
the node had a bad behavior in the past. A representative scheme is presented in CORE. CORE
evaluates neighbouring nodes based on direct observation, indirect observation that considers
only positive reports by others, and task-speciïn ˛Ac behavior. These are compiled by a weighted ˇ
trust technique, and the compiled result is used for discriminating and isolating a malicious
node from the network. CORE assigns higher weight to past behaviors than recent behavior
to minimize the influences of a recent bad behavior on the evaluation [6] . Note that BBR
is not a very good choice of redemption technique for systems in which nodes are isolated
from use when trust is low, because BBR relies on subsequent behaviors to allow trust to be
redeemed. Since trust is used to make decisions about collaboration, an untrusted node will not
have a chance to participate in the network, and therefore no new behaviors can be observed.
Here discuss this type of redemption scheme because it is a widely used technique for trust
redemption.
2.2.2 Time Based Redemption
If assume that a friend had a bad behavior in the past, we might decide not to trust the
friend for a while. After time has passed, we may expect the bad behavior was a mistake,
and give the friend another chance. This represents Time Based Redemption. Here provide
some time to a node to recover from a temporary error, and we give another opportunity to