Biblio

The hardware and low-level software in many mobile devices are capable of mobile-to-mobile communication, including ad-hoc 802.11, Bluetooth, and cognitive radios. We have started to leverage this capability to provide interpersonal communication both over infrastructure networks (the Internet), and over ad-hoc and delay-tolerant networks composed of the mobile devices themselves. This network is decentralized in the sense that it can function without any infrastructure, but does take advantage of infrastructure connections when available. All interpersonal communication is encrypted and authenticated so packets may be carried by devices belonging to untrusted others. The decentralized model of security builds a flexible trust network on top of the social network of communicating individuals. This social network can be used to prioritize packets to or from individuals closely related by the social network. Other packets are prioritized to favor packets likely to consume fewer network resources. Each device also has a policy that determines how many packets may be forwarded, with the goal of providing useful interpersonal communications using at most 1% of any given resource on mobile devices. One challenge in a fully decentralized network is routing. Our design uses Rendezvous Points (RPs) and Distributed Hash Tables (DHTs) for delivery over infrastructure networks, and hop-limited broadcast and Delay Tolerant Networking (DTN) within the wireless ad-hoc network.

Vehicular ad-hoc networks (VANETs) provides infrastructure less, rapidly deployable, self-configurable network connectivity. The network is the collection vehicles interlinked by wireless links and willing to store and forward data for their peers. As vehicles move freely and organize themselves arbitrarily, message routing is done dynamically based on network connectivity. Compared with other ad-hoc networks, VANETs are particularly challenging due to the part of the vehicles' high rate of mobility and the numerous signal-weakening barrier, such as buildings, in their environments. Due to their enormous potential, VANET have gained an increasing attention in both industry and academia. Research activities range from lower layer protocol design to applications and implementation issues. A secure VANET system, while exchanging information should protect the system against unauthorized message injection, message alteration, eavesdropping. The security of VANET is one of the most critical issues because their information transmission is propagated in open access (wireless) environments. A few years back VANET has received increased attention as the potential technology to enhance active and preventive safety on the road, as well as travel comfort Safekeeping and privacy are mandatory in vehicular communications for a grateful acceptance and use of such technology. This paper is an attempt to highlight the problems occurred in Vehicular Ad hoc Networks and security issues.

Tactical communication networks lack infrastructure and are highly dynamic, resource-constrained, and commonly targeted by adversaries. Designing efficient and secure applications for this environment is extremely challenging. An increasing reliance on group-oriented, tactical applications such as chat, situational awareness, and real-time video has generated renewed interest in IP multicast delivery. However, a lack of developer tools, software libraries, and standard paradigms to achieve secure and reliable multicast impedes the potential of group-oriented communication and often leads to inefficient communication models. In this paper, we propose an architecture for secure and reliable group-oriented communication. The architecture utilizes NSA Suite B cryptography and may be appropriate for handling sensitive and DoD classified data up to SECRET. Our proposed architecture is unique in that it requires no infrastructure, follows NSA CSfC guidance for layered security, and leverages NORM for multicast data reliability. We introduce each component of the architecture and describe a Linux-based software prototype.
 

The need for increased surveillance due to increase in flight volume in remote or oceanic regions outside the range of traditional radar coverage has been fulfilled by the advent of space-based Automatic Dependent Surveillance — Broadcast (ADS-B) Surveillance systems. ADS-B systems have the capability of providing air traffic controllers with highly accurate real-time flight data. ADS-B is dependent on digital communications between aircraft and ground stations of the air route traffic control center (ARTCC); however these communications are not secured. Anyone with the appropriate capabilities and equipment can interrogate the signal and transmit their own false data; this is known as spoofing. The possibility of this type of attacks decreases the situational awareness of United States airspace. The purpose of this project is to design a secure transmission framework that prevents ADS-B signals from being spoofed. Three alternative methods of securing ADS-B signals are evaluated: hashing, symmetric encryption, and asymmetric encryption. Security strength of the design alternatives is determined from research. Feasibility criteria are determined by comparative analysis of alternatives. Economic implications and possible collision risk is determined from simulations that model the United State airspace over the Gulf of Mexico and part of the airspace under attack respectively. The ultimate goal of the project is to show that if ADS-B signals can be secured, the situational awareness can improve and the ARTCC can use information from this surveillance system to decrease the separation between aircraft and ultimately maximize the use of the United States airspace.

In wireless networks, spoofing attack is one of the most common and challenging attacks. Due to these attacks the overall network performance would be degraded. In this paper, a medoid based clustering approach has been proposed to detect a multiple spoofing attacks in wireless networks. In addition, a Enhanced Partitioning Around Medoid (EPAM) with average silhouette has been integrated with the clustering mechanism to detect a multiple spoofing attacks with a higher accuracy rate. Based on the proposed method, the received signal strength based clustering approach has been adopted for medoid clustering for detection of attacks. In order to prevent the multiple spoofing attacks, dynamic MAC address allocation scheme using MD5 hashing technique is implemented. The experimental results shows, the proposed method can detect spoofing attacks with high accuracy rate and prevent the attacks. Thus the overall network performance is improved with high accuracy rate.
 

We provide a generic framework that, with the help of a preprocessing phase that is independent of the inputs of the users, allows an arbitrary number of users to securely outsource a computation to two non-colluding external servers. Our approach is shown to be provably secure in an adversarial model where one of the servers may arbitrarily deviate from the protocol specification, as well as employ an arbitrary number of dummy users. We use these techniques to implement a secure recommender system based on collaborative filtering that becomes more secure, and significantly more efficient than previously known implementations of such systems, when the preprocessing efforts are excluded. We suggest different alternatives for preprocessing, and discuss their merits and demerits.

Quantum cryptography and quantum search algorithm are considered as two important research topics in quantum information science. An asymmetrical quantum encryption protocol based on the properties of quantum one-way function and quantum search algorithm is proposed. Depending on the no-cloning theorem and trapdoor one-way functions of the public-key, the eavesdropper cannot extract any private-information from the public-keys and the ciphertext. Introducing key-generation randomized logarithm to improve security of our proposed protocol, i.e., one private-key corresponds to an exponential number of public-keys. Using unitary operations and the single photon measurement, secret messages can be directly sent from the sender to the receiver. The security of the proposed protocol is proved that it is information-theoretically secure. Furthermore, compared the symmetrical Quantum key distribution, the proposed protocol is not only efficient to reduce additional communication, but also easier to carry out in practice, because no entangled photons and complex operations are required.

Educational software systems have an increasingly significant presence in engineering sciences. They aim to improve students' attitudes and knowledge acquisition typically through visual representation and simulation of complex algorithms and mechanisms or hardware systems that are often not available to the educational institutions. This paper presents a novel software system for CryptOgraphic ALgorithm visuAl representation (COALA), which was developed to support a Data Security course at the School of Electrical Engineering, University of Belgrade. The system allows users to follow the execution of several complex algorithms (DES, AES, RSA, and Diffie-Hellman) on real world examples in a step by step detailed view with the possibility of forward and backward navigation. Benefits of the COALA system for students are observed through the increase of the percentage of students who passed the exam and the average grade on the exams during one school year.
 

Efficient and secure search on encrypted data is an important problem in computer science. Users having large amount of data or information in multiple documents face problems with their storage and security. Cloud services have also become popular due to reduction in cost of storage and flexibility of use. But there is risk of data loss, misuse and theft. Reliability and security of data stored in the cloud is a matter of concern, specifically for critical applications and ones for which security and privacy of the data is important. Cryptographic techniques provide solutions for preserving the confidentiality of data but make the data unusable for many applications. In this paper we report a novel approach to securely store the data on a remote location and perform search in constant time without the need for decryption of documents. We use bloom filters to perform simple as well advanced search operations like case sensitive search, sentence search and approximate search.
 

Encryption and decryption of data in an efficient manner is one of the challenging aspects of modern computer science. This paper introduces a new algorithm for Cryptography to achieve a higher level of security. In this algorithm it becomes possible to hide the meaning of a message in unprintable characters. The main issue of this paper is to make the encrypted message undoubtedly unprintable using several times of ASCII conversions and a cyclic mathematical function. Dividing the original message into packets binary matrices are formed for each packet to produce the unprintable encrypted message through making the ASCII value for each character below 32. Similarly, several ASCII conversions and the inverse cyclic mathematical function are used to decrypt the unprintable encrypted message. The final encrypted message received from three times of encryption becomes an unprintable text through which the algorithm possesses higher level of security without increasing the size of data or loosing of any data.
 

Modern cyber systems and their integration with the infrastructure has a clear effect on the productivity and quality of life immensely. Their involvement in our daily life elevate the need for means to insure their resilience against attacks and failure. One major threat is the software monoculture. Latest research work demonstrated the danger of software monoculture and presented diversity to reduce the attack surface. In this paper, we propose ChameleonSoft, a multidimensional software diversity employment to, in effect, induce spatiotemporal software behavior encryption and a moving target defense. ChameleonSoft introduces a loosely coupled, online programmable software-execution foundation separating logic, state and physical resources. The elastic construction of the foundation enabled ChameleonSoft to define running software as a set of behaviorally-mutated functionally-equivalent code variants. ChameleonSoft intelligently Shuffle, at runtime, these variants while changing their physical location inducing untraceable confusion and diffusion enough to encrypt the execution behavior of the running software. ChameleonSoft is also equipped with an autonomic failure recovery mechanism for enhanced resilience. In order to test the applicability of the proposed approach, we present a prototype of the ChameleonSoft Behavior Encryption (CBE) and recovery mechanisms. Further, using analysis and simulation, we study the performance and security aspects of the proposed system. This study aims to assess the provisioned level of security by measuring the avalanche effect percentage and the induced confusion and diffusion levels to evaluate the strength of the CBE mechanism. Further, we compute the computational cost of security provisioning and enhancing system resilience.

This paper presents an overview of cyber maneuvers and their roles in cyber security. As the cyber war escalates, a strategy that preemptively limits and curtails attacks is required. Such a proactive strategy is called a cyber maneuver and is a refinement of the concept of a moving-target defense, which includes both reactive and proactive network changes. The major advantages of cyber maneuvers relative to other moving-target defenses are described. The use of maneuver keys in making cyber maneuvers much more feasible and affordable is explained. As specific examples, the applications of maneuver keys in encryption algorithms and as spread-spectrum keys are described. The integration of cyber maneuvers into a complete cyber security system with intrusion detection, identification of compromised nodes, and secure rekeying is presented. An example of secure rekeying despite the presence of compromised nodes is described.
 

Wireless information security generates shared secret keys from reciprocal channel dynamics. Current solutions are mostly based on temporal per-frame channel measurements of signal strength and suffer from low key generate rate (KGR), large budget in channel probing, and poor secrecy if a channel does not temporally vary significantly. This paper designs a cross-layer solution that measures noise-free per-symbol channel dynamics across both time and frequency domain and derives keys from the highly fine-grained per-symbol reciprocal channel measurements. This solution consists of merits that: (1) the persymbol granularity improves the volume of available uncorrelated channel measurements by orders of magnitude over per-frame granularity in conventional solutions and so does KGR; 2) the solution exploits subtle channel fluctuations in frequency domain that does not force users to move to incur enough temporal variations as conventional solutions require; and (3) it measures noise-free channel response that suppresses key bit disagreement between trusted users. As a result, in every aspect, the proposed solution improves the security performance by orders of magnitude over conventional solutions. The performance has been evaluated on both a GNU SDR testbed in practice and a local GNU Radio simulator. The cross-layer solution can generate a KGR of 24.07 bits per probing frame on testbed or 19 bits in simulation, although conventional optimal solutions only has a KGR of at most one or two bit per probing frame. It also has a low key bit disagreement ratio while maintaining a high entropy rate. The derived keys show strong independence with correlation coefficients mostly less than 0.05. Furthermore, it is empirically shown that any slight physical change, e.g. a small rotation of antenna, results in fundamentally different cross-layer frequency measurements, which implies the strong secrecy and high efficiency of the proposed solution.
 

This paper proposed a MIMO cross-layer precoding secure communications via pattern controlled by higher layer cryptography. By contrast to physical layer security system, the proposed scheme could enhance the security in adverse situations where the physical layer security hardly to be deal with. Two One typical situation is considered. One is that the attackers have the ideal CSI and another is eavesdropper's channel are highly correlated to legitimate channel. Our scheme integrates the upper layer with physical layer secure together to gaurantee the security in real communication system. Extensive theoretical analysis and simulations are conducted to demonstrate its effectiveness. The proposed method is feasible to spread in many other communicate scenarios.
 

Virtualized environments are widely thought to cause problems for software-based random number generators (RNGs), due to use of virtual machine (VM) snapshots as well as fewer and believed-to-be lower quality entropy sources. Despite this, we are unaware of any published analysis of the security of critical RNGs when running in VMs. We fill this gap, using measurements of Linux's RNG systems (without the aid of hardware RNGs, the most common use case today) on Xen, VMware, and Amazon EC2. Despite CPU cycle counters providing a significant source of entropy, various deficiencies in the design of the Linux RNG makes its first output vulnerable during VM boots and, more critically, makes it suffer from catastrophic reset vulnerabilities. We show cases in which the RNG will output the exact same sequence of bits each time it is resumed from the same snapshot. This can compromise, for example, cryptographic secrets generated after resumption. We explore legacy-compatible countermeasures, as well as a clean-slate solution. The latter is a new RNG called Whirlwind that provides a simpler, more-secure solution for providing system randomness.
 

With the advent of social networks and cloud computing, the amount of multimedia data produced and communicated within social networks is rapidly increasing. In the mean time, social networking platform based on cloud computing has made multimedia big data sharing in social network easier and more efficient. The growth of social multimedia, as demonstrated by social networking sites such as Facebook and YouTube, combined with advances in multimedia content analysis, underscores potential risks for malicious use such as illegal copying, piracy, plagiarism, and misappropriation. Therefore, secure multimedia sharing and traitor tracing issues have become critical and urgent in social network. In this paper, we propose a scheme for implementing the Tree-Structured Harr (TSH) transform in a homomorphic encrypted domain for fingerprinting using social network analysis with the purpose of protecting media distribution in social networks. The motivation is to map hierarchical community structure of social network into tree structure of TSH transform for JPEG2000 coding, encryption and fingerprinting. Firstly, the fingerprint code is produced using social network analysis. Secondly, the encrypted content is decomposed by the TSH transform. Thirdly, the content is fingerprinted in the TSH transform domain. At last, the encrypted and fingerprinted contents are delivered to users via hybrid multicast-unicast. The use of fingerprinting along with encryption can provide a double-layer of protection to media sharing in social networks. Theory analysis and experimental results show the effectiveness of the proposed scheme.
 

Secure data communication is the most important and essential issue in the area of message transmission over the networks. Cryptography provides the way of making secure message for confidential message transfer. Cryptography is the process of transforming the sender's message to a secret format called cipher text that only intended receiver will get understand the meaning of the secret message. There are various cryptographic or DNA based encoding algorithms have been proposed in order to make secret message for communication. But all these proposed DNA based encryption algorithms are not secure enough to provide better security as compared with the today's security requirement. In this paper, we have proposed a technique of encryption that will enhance the message security. In this proposed algorithm, a new method of DNA based encryption with a strong key of 256 bit is used. Along with this big size key various other encoding tools are used as key in the encoding process of the message like random series of DNA bases, modified DNA bases coding. Moreover a new method of round key selection is also given in this paper to provide better security in the message. The cipher text contains the extra bit of information as similar with the DNA strands that will provide better and enhanced security against intruder's attack.
 

With the advancement in technology, industry, e-commerce and research a large amount of complex and pervasive digital data is being generated which is increasing at an exponential rate and often termed as big data. Traditional Data Storage systems are not able to handle Big Data and also analyzing the Big Data becomes a challenge and thus it cannot be handled by traditional analytic tools. Cloud Computing can resolve the problem of handling, storage and analyzing the Big Data as it distributes the big data within the cloudlets. No doubt, Cloud Computing is the best answer available to the problem of Big Data storage and its analyses but having said that, there is always a potential risk to the security of Big Data storage in Cloud Computing, which needs to be addressed. Data Privacy is one of the major issues while storing the Big Data in a Cloud environment. Data Mining based attacks, a major threat to the data, allows an adversary or an unauthorized user to infer valuable and sensitive information by analyzing the results generated from computation performed on the raw data. This thesis proposes a secure k-means data mining approach assuming the data to be distributed among different hosts preserving the privacy of the data. The approach is able to maintain the correctness and validity of the existing k-means to generate the final results even in the distributed environment.
 

Due to the high volume and velocity of big data, it is an effective option to store big data in the cloud, because the cloud has capabilities of storing big data and processing high volume of user access requests. Attribute-Based Encryption (ABE) is a promising technique to ensure the end-to-end security of big data in the cloud. However, the policy updating has always been a challenging issue when ABE is used to construct access control schemes. A trivial implementation is to let data owners retrieve the data and re-encrypt it under the new access policy, and then send it back to the cloud. This method incurs a high communication overhead and heavy computation burden on data owners. In this paper, we propose a novel scheme that enabling efficient access control with dynamic policy updating for big data in the cloud. We focus on developing an outsourced policy updating method for ABE systems. Our method can avoid the transmission of encrypted data and minimize the computation work of data owners, by making use of the previously encrypted data with old access policies. Moreover, we also design policy updating algorithms for different types of access policies. The analysis show that our scheme is correct, complete, secure and efficient.
 

The main objective of this research is to build upon existing cryptographic standards and web protocols to design an alternative multi-factor authentication cryptosystem for the web. It involves seed exchange to a software-based token through a login-protected Transport Layer Security (TLS/SSL) tunnel, encrypted local storage through a password-protected keystore (BC UBER) with a strong key derivation function (PBEWithSHAANDTwofish-CBC), and offline generation of one-time passwords through the TOTP algorithm (IETF RFC 6239). Authentication occurs through the use of a shared secret (the seed) to verify the correctness of the one-time password used to authenticate. With the traditional use of username and password no longer wholly adequate for protecting online accounts, and with regulators worldwide toughening up security requirements (i.e. BSP 808, FFIEC), this research hopes to increase research effort on further development of cryptosystems involving multi-factor authentication.
 

The Internet of Things is a vision that broadens the scope of the internet by incorporating physical objects to identify themselves to the participating entities. This innovative concept enables a physical device to represent itself in the digital world. There are a lot of speculations and future forecasts about the Internet of Things devices. However, most of them are vendor specific and lack a unified standard, which renders their seamless integration and interoperable operations. Another major concern is the lack of security features in these devices and their corresponding products. Most of them are resource-starved and unable to support computationally complex and resource consuming secure algorithms. In this paper, we have proposed a lightweight mutual authentication scheme which validates the identities of the participating devices before engaging them in communication for the resource observation. Our scheme incurs less connection overhead and provides a robust defence solution to combat various types of attacks.
 

ID/password-based authentication is commonly used in network services. Some users set different ID/password pairs for different services, but other users reuse a pair of ID/password to other services. Such recycling allows the list attack in which an adversary tries to spoof a target user by using a list of IDs and passwords obtained from other system by some means (an insider attack, malwares, or even a DB leakage). As a countermeasure agains the list attack, biometric authentication attracts much attention than before. In 2012, Hattori et al. proposed a cancelable biometrics authentication scheme (fundamental scheme) based on homomorphic encryption algorithms. In the scheme, registered biometric information (template) and biometric information to compare are encrypted, and the similarity between these biometric information is computed with keeping encrypted. Only the privileged entity (a decryption center), who has a corresponding decryption key, can obtain the similarity by decrypting the encrypted similarity and judge whether they are same or not. Then, Hirano et al. showed the replay attack against this scheme, and, proposed two enhanced authentication schemes. In this paper, we propose a spoofing attack against the fundamental scheme when the feature vector, which is obtained by digitalizing the analogue biometric information, is represented as a binary coding such as Iris Code and Competitive Code. The proposed attack uses an unexpected vector as input, whose distance to all possible binary vectors is constant. Since the proposed attack is independent from the replay attack, the attack is also applicable to two revised schemes by Hirano et al. as well. Moreover, this paper also discusses possible countermeasures to the proposed spoofing attack. In fact, this paper proposes a countermeasure by detecting such unexpected vector.
 

Visual cryptography is a way to encrypt the secret image into several meaningless share images. Noted that no information can be obtained if not all of the shares are collected. Stacking the share images, the secret image can be retrieved. The share images are meaningless to owner which results in difficult to manage. Tagged visual cryptography is a skill to print a pattern onto meaningless share images. After that, users can easily manage their own share images according to the printed pattern. Besides, access control is another popular topic to allow a user or a group to see the own authorizations. In this paper, a self-authentication mechanism with lossless construction ability for image secret sharing scheme is proposed. The experiments provide the positive data to show the feasibility of the proposed scheme.
 

Wireless network, whether it's ad-hoc or at enterprise level is vulnerable due to its features of open medium, and usually due to weak authentication, authorization, encryption, monitoring and accounting mechanisms. Various wireless vulnerability situations as well as the minimal features that are required in order to protect, monitor, account, authenticate, and authorize nodes, users, computers into the network are examined. Also, aspects of several IEEE Security Standards, which were ratified and which are still in draft are described.
 

File encryption is an effective way for an enterprise to prevent its data from being lost. However, the data may still be deliberately or inadvertently leaked out by the insiders or customers. When the sensitive data are leaked, it often results in huge monetary damages and credit loss. In this paper, we propose a novel group file encryption/decryption method, named the Group File Encryption Method using Dynamic System Environment Key (GEMS for short), which provides users with auto crypt, authentication, authorization, and auditing security schemes by utilizing a group key and a system environment key. In the GEMS, the important parameters are hidden and stored in different devices to avoid them from being cracked easily. Besides, it can resist known-key and eavesdropping attacks to achieve a very high security level, which is practically useful in securing an enterprise's and a government's private data.