International Journal of Engineering Trends and Technology (IJETT) – Volume 23 Number 8- May 2015 Enhanced DTN Using Polynomial Hash Function for Attribute Abstraction Shree Harsha M R#1, Pradeep Kumar H S*2 1 M.Tech Student, Computer Science, Maharaja Institute of Technology, Mysore Karnataka, India 2 Asst. Professor, Computer Science, Maharaja Institute of Technology, Mysore Karnataka, India Abstract— Disruption tolerant networks (DTNs) allow for routing in networks where connection is not continious always and contemporaneous end-to-end paths are unstable or unlikely. These behaviours create bottlenecks like high node mobility, low short radio range; environmental interference and obstruction; and denial-of-service attacks. Need for a secured network where storage, transmission and receiving of confidential data are never compromised is of great demand. One way hash function has the approach like cheap enough for the intended users and prohibitively challenging for any malicious agent. A public key component is defined for each user attribute. When encrypting the message, the encryptor chooses an access structure on attributes, and encrypts the message under the access structure via encrypting with the corresponding public key components. Intended users are provided with keys generated by random pairwise pre key distribution scheme. Users are able to decrypt a ciphertext if and only if their attributes satisfy the ciphertext access structure. Todays secured systems are being proven unsecured and there is a great need for new ideas in providing efficient ways to achieve that. Whenever a packet is sent from one DTN node to another it is important to keep track of the previously sent packets or the next coming packets transmission. In working of regular internet, sync ACK is sent by the sender along with the packet and as soon as receiver receives the packet, it retransmits ACK packet to sender confirming proper receiving of the packet. Keywords— Key pre distribution, static polynomial pool, 1-way hash chain, replication attack I. INTRODUCTION An important factor which decides a nations strength is its Military force. It includes both attacking and defensive capabilities. Military expeditions include a high level complex planning and precised executions. It varies from a group of intellectuals planning under single roof to a group of welltrained commandos executing that plan at any part of the globe. Military is not like any other wing which works inside a single building or nearby area. It must spread its arms across invariant distances, unexplored parts of the globe under varying weather conditions.Typical Internet depends on endto-end continuous connectivity to work. Reliability requires end-to-end acknowledgements. Major drawback is, when this direct link is disconnected, the incoming packets are simply dropped at the point of disconnection, which results in loss of data. Communication is the most important thing in military. Providing security to the communication part is one of the greatest challenges. As soldiers travel through various types of environmental ambience, they experience scenarios where communication is no longer possible or almost nill. This also increases the fear of mis-communication, interference, manipulation of information and also information destruction. ISSN: 2231-5381 Fig -1: Custody Transfer at Bundle Protocol In DTN approach, a packet must be able to wait for some time at different intermediate storage nodes due to the unavailability of the continuous connection. During this process, the bundle protocol uses Custody Transfer Mechanism, which ensures the transmission of packets from one storage node to another. http://www.ijettjournal.org Page 400 International Journal of Engineering Trends and Technology (IJETT) – Volume 23 Number 8- May 2015 Fig -2: Routing using Bundle Protocol During this process, the bundle protocol uses Custody Transfer Mechanism, which ensures the transmission of packets from one storage node to another. A. Characteristics of DTN 1) High queue delay: Every hop delay might be very high because of the DTN intermittent connectivity keeps unreachable in a very long time. Overall delay consists of Waiting, Queuing and Transmission time. 2) Limitted Resource: The capacity of a node in terms of processing ability, computing ability and storage space is weaker when compared with capacity of a ordinary computer. II. RELATED STUDY It is reported that the properties related to identities can be in the form of expandable attributes. The problem of, attributes being held by users forever is attended by ABE efficiently by adding timers with expiry information to revoke private keys. Attributes that are invariable are not updated resulting in saving considerable amount of CPU resources, time and bandwidth. Private keys are generated using random numbers which reduces the possibilities of a user sharing his attribute with others or borrowing attributes from his expired private keys[1]. As per John Burgess, idea of Maxprop effectively handles existing approaches where it has affinity towards less distant destinations by using the total number of hops in packets to calculate the fairness allotment of network resources. Existing approaches have the problem of removing stale data or out dated data from buffers used in the network. Maxprop efficiently maintains a detailed list of past intermediaries thus by not allowing data to traverse same node twice. In Maxprop, each peer is made to carry all messages until the packet is said to meet the next occurring. Single peer starts forwarding message to infinite number of other peers until its replica of the message times out. This action is either notified of the carried delivery by sending an ack, or due to the overflow of the buffer, the message is dropped[2]. B. Problems in Existing System The problem of key revocation [13] is a major issue in providing secure communication in existing system as the associated attributes of user can undergo change at any time. III. PROPOSED METHOD 3) Limited Life time of node: Considering special scenarios of the restricted network, the node is made to depend for power of hostile environment or in extreme conditions, which will reduce the lifetime of the node. 4) Dynamic topology: Because of the environmental changes, energy depletion and other failures, DTN topology changes dynamically which results in dropping out of network. Also, requirements of getting in to DTN also make topology change. 5) Weak Security: In general threats of wireless communication like- eavesdropping, routing spoofing, message modification, Denial of Service (DoS) are the major hurdles due to poor maintenance and unavailability of dedicated services in realworld. 6) Heterogeneous interconnection: Since DTN gateway ensures reliable transmission of interconnection message, it can run on various heterogeneous network protocol stacks with the help of introduction of Bundle layer. ISSN: 2231-5381 In this paper we identified and addressed above mentioned problem. We have developed a general framework with the usage of pair wise key pre-distribution scheme as its basic components to provide authentication and pairwise key establishment between sensor nodes and mobile sinks. This provides a better and strong mechanisms to provide authentication issues and strategically reduces the problem of key escrow trustiness. As of to study a new security technique we first cultivated a general three-tier security framework ([11]) for authentication and pairwise key establishment ([7],[8], [9]), based on the polynomial pool based key pre distribution scheme[12]. To meet the three-tier security scheme with the ability of being more robust against a stationary access node replication attack, we have emphasised and strengthened the authentication mechanism between sessionly access node and sensor nodes using 1-way hash chain algorithm in conjunction http://www.ijettjournal.org Page 401 International Journal of Engineering Trends and Technology (IJETT) – Volume 23 Number 8- May 2015 with the static polynomial pool based scheme. compared to the single polynomial pool based key pre distribution approach, as an attacker would have to compromise many more sensor nodes to launch successful mobile sink replication attacks. CONCLUSION DTN technologies are becoming successful solutions in military applications that allow wireless devices to communicate with each other and access the confidential information reliably by exploiting external storage nodes. Our enhanced ABE is a scalable cryptographic solution to the access control and secure data retrieval issues. Reduced computational cost makes it efficient to implement. Fig -3: 3-tier security architecture ACKNOWLEDGMENT I would like to give my sincere gratitude to my guide Pradeep Kumar H S who encouraged and guided me throughout this paper with the new ideas and innovative knowledge. REFERENCES IV. EXPERIMENTAL RESULT [1]. D. Huang and M. Verma, “ASPE: Attribute-based secure policy Our analytical results indicates that the new security technique has an increase in efficiency factor of 38% when compared with the regular DTN approach. It is also more resilient to both mobile sink replication attacks and stationary access nodes replications attack compared to the single polynomial pool based approach. The below graph shows a scenario where performance is evaluated with respect to robustness and secured communication among many number of users against time frames, each of 10hours time duration. enforcement in vehicular ad hoc networks,” Ad Hoc Netw., vol. 7, no. 8, pp. 1526–1535, 2009. [2]. J. Burgess, B. Gallagher, D. Jensen, and B. N. Levine, “Maxprop: Routing for vehicle-based disruption tolerant networks,” in Proc. IEEE INFOCOM, 2006, pp. 1–11. [3]. S. Roy andM. Chuah, “Secure data retrieval based on ciphertext policy attribute-based encryption (CP-ABE) system for the DTNs,” Lehigh CSE Tech. Rep., 2009. [4]. M. Kallahalla, E. Riedel, R. Swaminathan, Q. Wang, and K. Fu, “Plutus: Scalable secure file sharing on untrusted storage,” in Proc. Conf. File Storage Technol., 2003, pp. 29–42. [5] V. Goyal, O. Pandey, A. Sahai, and B. Waters, “Attribute-based encryption for fine-grained access control of encrypted data,” in Proc. ACM Conf. Comput. Commun. Security, 2006, pp. 89–98. [6] J. Bethencourt, A. Sahai, and B. Waters, “Ciphertext-policy attributebased encryption,” in Proc. IEEE Symp. Security Privacy, 2007, pp. 321–334. [7] AES Key Wrap Specification, NIST, November 16, 2001. [8] ANS X9.62-2 Elliptic Curve Digital Signature Algorithm (ECDSA), November 16, 2005. [9] FIPS 180-2, Secure Hash Standard, August 2002. [10] H. Chan, A. Perrig, and D. Song,"Random Key Pre-Distribution Schemes for Sensor Networks", Proc. IEEE Symp. Research in Security and Privacy, 2003 [11] A. Rasheed and R. Mahapatra, "Three-Tier security scheme in wireless sensor network with mobile sink", IEEE Transaction on parallel and distributed system,vol-23,no.5,May-2012 [12] A. Rasheed and R. Mahapatra,"Key predistribution schemes for establishing pairwise keys with a mobile sink in sensor network", IEEE Transaction on parallel and distributed system,vol-22,no.5,January 2011. [13] L. Eschenauer and V.D. Gligor,"Key-Management Scheme for Distributed Sensor Networks", Proc. ACM Conf. Computer Comm. Security (CCS ’02), pp. 41-47, 2002 Advantage of the proposed system is that it substantially improves networks resilient to mobile sink replication attacks ISSN: 2231-5381 http://www.ijettjournal.org Page 402