Biblio

Communication is an essential part of everyday life, both as a social interaction and collaboration to achieve goals. Wireless technology has effectively release the users to roam more freely to achieving collaboration and communication. The principle attraction of mobile ad hoc networks (MANET) are their set-up less and decentralized action. However, mobile ad hoc networks are seen as relatively easy targets for attackers. Security in mobile ad hoc network is provided by encrypting the data when exchanging messages and key management. Cryptography is therefore vital to ensure privacy of message and robustness against disruption. The proposed scheme public string based threshold cryptography (PSTC) describes the new scheme based on threshold cryptography that provides reasonably secure and robust cryptography scheme for mobile ad hoc networks. The scheme is implemented and simulated in ns-2. The scheme is based on trust value and analyze against Denial of Service attack as node found the attacker, the node reject all packet from that attacker. In proposed scheme whole network is compromised only when all nodes of network is compromised because threshold nodes only sharing public string not the master private key. The scheme provides confidentiality and integrity. The default threshold value selected is 2 according to time and space analysis.

Today's extensive use of Internet creates huge volumes of data by users in both client and server sides. Normally users don't want to store all the data in local as well as keep archive in the server. For some unwanted data, such as trash, cache and private data, needs to be deleted periodically. Explicit deletion could be applied to the local data, while it is a troublesome job. But there is no transparency to users on the personal data stored in the server. Since we have no knowledge of whether they're cached, copied and archived by the third parties, or sold by the service provider. Our research seeks to provide an automatic data sanitization system to make data could be self-destructing. Specifically, we give data a life cycle, which would be erased automatically when at the end of its life, and the destroyed data cannot be recovered by any effort. In this paper, we present FlashGhost, which is a system that meets this challenge through a novel integration of cryptography techniques with the frequent colliding hash table. In this system, data will be unreadable and rendered unrecoverable by overwriting multiple times after its validity period has expired. Besides, the system reliability is enhanced by threshold cryptography. We also present a mathematical model and verify it by a number of experiments, which demonstrate theoretically and experimentally our system is practical to use and meet the data auto-sanitization goal described above.

Threshold cryptography provides a mechanism for protecting secret keys by sharing them among multiple parties, who then jointly perform cryptographic operations. An attacker who corrupts up to a threshold number of parties cannot recover the secrets or violate security. Prior works in this space have mostly focused on definitions and constructions for public-key cryptography and digital signatures, and thus do not capture the security concerns and efficiency challenges of symmetric-key based applications which commonly use long-term (unprotected) master keys to protect data at rest, authenticate clients on enterprise networks, and secure data and payments on IoT devices. We put forth the first formal treatment for distributed symmetric-key encryption, proposing new notions of correctness, privacy and authenticity in presence of malicious attackers. We provide strong and intuitive game-based definitions that are easy to understand and yield efficient constructions. We propose a generic construction of threshold authenticated encryption based on any distributed pseudorandom function (DPRF). When instantiated with the two different DPRF constructions proposed by Naor, Pinkas and Reingold (Eurocrypt 1999) and our enhanced versions, we obtain several efficient constructions meeting different security definitions. We implement these variants and provide extensive performance comparisons. Our most efficient instantiation uses only symmetric-key primitives and achieves a throughput of upto 1 million encryptions/decryptions per seconds, or alternatively a sub-millisecond latency with upto 18 participating parties.

Dependency on cloud computing are increasing day by day due to its beneficial aspects. As day by day we are relying on cloud computing, the securities issues are coming up. There are lots of security protocols but now-a-days those protocol are not secured enough to provide a high security. One of those protocols which were once highly secured, is Kerberos authentication protocol. With the advancement of technology, Kerberos authentication protocol is no longer as secured as it was before. Many authors have thought about the improvement of Kerberos authentication protocol and consequently they have proposed different types of protocol models by using a renowned public key cryptography named RSA cryptography. Though RSA cryptography is good to some extent but this cryptography has some flaws that make this cryptography less secured as well as less efficient. In this paper, we are combining Elliptic Curve Cryptography (ECC) as well as Threshold Cryptography to create a new version of Kerberos authentication protocol. Our proposed model will provide secure transaction of data which will not only be hard to break but also increase memory efficiency, cost efficiency, and reduce the burden of computation.

Since MANETs are infrastructure-less, they heavily use secret sharing techniques to distribute and decentralize the role of a trusted third party, where the MANET secret s is shared among the legitimate nodes using (t, n) threshold secret sharing scheme. For long lived MANETs, the shared secret is periodically updated without changing the MANET secret based on proactive secret sharing using Elliptic Curve Cryptography(ECC). Hence, the adversary trying to learn the secret, needs to gain at-least t partial shares in the same time period. If the time period and the threshold value t are selected properly, proactive verifiable secret sharing can maintain the overall security of the information in long lived MANETs. The conventional cryptographic algorithms are heavy weight, require lot of computation power thus consuming lot of resources. In our proposal we used Elliptic Curve Cryptography to verify commitments as it requires smaller keys compared to existing proactive secret sharing techniques and makes it useful for MANETs, Which are formed of resource constraint devices.