Nt1320 Unit 3

The attacker correlates the packet transmission times of each node and traces the packets hop-by-hop from its source to its destination. The intuition here is that under normal scenarios, each intermediate forwarder will forward a packet towards its destination without adding additional delay or packet mixing. Privacy can be enhanced when each forwarder node adds a random delay before transmitting the packet ~\cite{zhang2012, shao2008} or route the packets to fake destinations~\cite{deng2005}.

Non repudiation: It ensures that nodes in the MANETs should not deny their responsibility of actions while sending and receiving the data packets. With the help of

4. In the last step, the nodes which is sending the rouge data packets , if that node will receive control packets from any node then that node will be detected as the malicious node which is responsible to trigger grayhole attack.

It just sends UDP echo packet in place of ICMP. This invasion can be very serious because of the 'stateless' property of UDP. This means there is no acknowledgement mechanism in this protocol, which makes UDP favorable for DoS attack. Attacker swallows up the network by UDP packets. Because of there is no mechanism, receiver can't identify the fake requests.

The paper presents an encryption method which is presented with the unusual property that publicly revealing an encryption key does not result in revealing the corresponding decryption key. It has two important consequences

To address the internal unlinkan\bility and increase the robustness of the DoS attacks, different authors have proposed a decentralized protocol that will co-ordinate the coin theft. The high mixing times also requires the separate honest peer mixings.

the shortest path to a destination. Believing these false route replies, source transmits data packets to the malicious node. The malicious node captures the data packets and drops them instead of transmitting them to destination.

In this variety of attack, a malicious node tries to inject pretend messages or routing packets to disrupt the routing mechanism. Such attacks square measure tough to observe in a very Edouard MANET since the routing packets seem to be legitimate packets to the nodes process them. The subsequent attacks square measure samples of attacks by fabrication [13]

MANETs are a kind of wireless ad hoc network (WANET) that usually has a routable networking environment on top of a Link Layer ad hoc network. Advantage in MANETs is consisting of a peer-to-peer, self-forming, self-healing network. Key agreement protocols are one of the fundamental primitives of cryptography, and allow users to establish session keys securely in the presence of an active adversary. For this we use verifiable secret sharing (VSS) and bilinear concepts in our project. In cryptography, a secret sharing scheme is verifiable when the nodes are allowed to verify their shares as consistent. A VSS has three phases: a Distribution phase, Verification phase and Reconstruction phase. We implement the verification property of VSS in verifying shares. This property is additionally ensured with the help of commitments in secret sharing schemes like Shamir‘s secret sharing. We proceed by having knowledge on adhoc on demand routing protocol (AODV), Destination Sequence distance vector (DSDV) protocols and using them in ns-2. In this project nodes verify shares through commitments when the source sends shares of secret key to destination on multiple ways and the destination reconstructs it by collecting all individual shares. After keys sharing, the encrypted packets are send from source to destination at a specified time during runtime.

Secure Multi-Party Communication: Ensures that parties that are participating in the communication learns nothing from the communication exchanged between them except the output of the computations and his input [7, Page7]. This protocol is needed because most computations are distributed, with the results of the computations exchanged via communication.

Ever since the creation of proxy signatures by Mambo et al [ ] in 1996, different variation of proxy signatures like self proxy signatures [], designated verifier proxy [] , and many more have been created by the researchers and one of them is nominative proxy signatures also. These signatures gives signing rights to proxy signer, to sign the message intended for the nominee in a way that nominee is the only person to verify the signature. Nominative proxy signatures are of two types: original nominative proxy signatures where original signer nominates the nominee and proxy nominative proxy signatures where proxy signer can nominate the nominee. Moreover, this signature satisfies all the basic properties of proxy signatures.

Ariadne can be implemented in three ways to authenticate routing messages: sharing of secret keys between all pair of nodes, TESLA (broadcasting authentication) with sharing of secret keys, and digital signatures. Sharing secret keys between nodes “requires n (n-1)/2 keys to be established in the network” (Anjum, 2007), the keys can be installed by the key distribution center before message routing. This type of approach creates administrative (someone to distribute the keys) and scalability (time delay) challenges¬¬. The TESLA approach requires the same type of process as the first, but it adds a single message authentication code (MAC) to a request message, this creates a security issue when broadcasting the message where the receiver can impersonate the sender. TESLA then uses one-way hash chain and clock synchronization to prevent this. The third implementation requires each node to have a set of asymmetric key and in short requires each node to have certain computational capability. The focus will be on TESLA implementation assuming each commination share a MAC key, every node has one-way hash chain capability, all nodes know the authentication key of the TESLA one-way key chain of every other node, and sender trust the destination source.

* The downside of this implementation is its high cost. Also, it may take a longtime to get a return on the investment.

In [10], author proposed a scheme which identifies the malicious nodes by using aggregate signature algorithm. It associates three algorithms.

Generally, every public-key digital signature schemes is based on a mathematical problem. This problem is known as NP (Non-deterministic polynomial) hard problem. The problem is considered to be an NP hard mathematical problem if the validity of a proposed solution can be checked only in polynomial time.