Biblio

Polar codes are a talented coding technique with the ability to accomplish the discrete memoryless channel capacity for modern communication systems with high reliability, but it is not secured enough for such systems. A secured system counts on grouping polar codes with secret Mersenne- Twister pseudo-random number generator (MT PRNG) is presented in this paper. The proposed encoder security is deduced from the secret pre-shared initial state of MT PRNG which is considered as the crypto-system ciphering key. The generated sequences are random like and control the frozen bits' values and their indices in the polarized bit channels. When the decoding cipher key at the receiver has one-bit change from the original encoding cipher key, the receiver has an almost 0.5 BER probability. This means that the receiver, in this case, had no clue about the originally sent information data bits without prior knowledge of the utilized 232-bit ciphering key. Moreover, the security of the system can be enhanced by utilizing a pseudo-random number generator (PRBG) with longer seed to increase the system secrecy and decoding obscurity.

Diffie-Hellman and RSA encryption/decryption involve computationally intensive cryptographic operations such as modular exponentiation. Computing modular exponentiation using appropriate pre-computed pairs of bases and exponents was first proposed by Boyko et al. In this paper, we present a reconfigurable architecture for pre-computation methods to compute modular exponentiation and thereby speeding up RSA and Diffie-Hellman like protocols. We choose Diffie-Hellman key pair (a, ga mod p) to illustrate the efficiency of Boyko et al's scheme in hardware architecture that stores pre-computed values ai and corresponding gai in individual block RAM. We use a Pseudo-random number generator (PRNG) to randomly choose ai values that are added and corresponding gai values are multiplied using modular multiplier to arrive at a new pair (a, ga mod p). Further, we present the advantage of using Montgomery and interleaved methods for batch multiplication to optimise time and area. We show that a 1024-bit modular exponentiation can be performed in less than 73$μ$s at a clock rate of 200MHz on a Xilinx Virtex 7 FPGA.

The RFID based communication between objects within the framework of IoT is potentially very efficient in terms of power requirements and system complexity. The new design incorporating the emerging chipless RFID tags has the potential to make the system more efficient and simple. However, these systems are prone to privacy and security risks and these challenges associated with such systems have not been addressed appropriately in the broader IoT framework. In this context, a lightweight collision free algorithm based on n-bit pseudo random number generator, X-OR hash function, and rotations for chipless RFID system is presented. The algorithm has been implemented on an 8-bit open-loop resonator based chipless RFID tag based system and is validated using BASYS 2 FPGA board based platform. The proposed scheme has been shown to possess security against various attacks such as Denial of Service (DoS), tag/reader anonymity, and tag impersonation.

Blum-Blum-Shub (BBS) is a less complex pseudorandom number generator (PRNG) that requires very large modulus and a squaring operation for the generation of each bit, which makes it computationally heavy and slow. On the other hand, the concept of elliptic curve (EC) point operations has been extended to PRNGs that prove to have good randomness properties and reduced latency, but exhibit dependence on the secrecy of point P. Given these pros and cons, this paper proposes a new BBS-ECPRNG approach such that the modulus is the product of two elliptic curve points, both primes of length, and the number of bits extracted per iteration is by binary fraction. We evaluate the algorithm performance by generating 1000 distinct sequences of 106bits each. The results were analyzed based on the overall performance of the sequences using the NIST standard statistical test suite. The average performance of the sequences was observed to be above the minimum confidence level of 99.7 percent and successfully passed all the statistical properties of randomness tests.

Radio Frequency IDentification(RFID) is one of the most important sensing techniques for Internet of Things(IoT) and RFID systems have been applied to various different fields. But an RFID system usually uses open wireless radio wave to communicate and this will lead to a serious threat to its privacy and security. The current popular RFID tags are some low-cost passive tags. Their computation and storage resources are very limited. It is not feasible for them to complete some complicated cryptographic operations. So it is very difficult to protect the security and privacy of an RFID system. Lightweight authentication protocol is considered as an effective approach. Many typical authentication protocols usually use Hash functions so that they require more computation and storage resources. Based on CRC function, we propose a lightweight RFID authentication protocol, which needs less computation and storage resources than Hash functions. This protocol exploits an on-chip CRC function and a pseudorandom number generator to ensure the anonymity and freshness of communications between reader and tag. It provides forward security and confidential communication. It can prevent eavesdropping, location trace, replay attack, spoofing and DOS-attack effectively. It is very suitable to be applied to RFID systems.

In December 2015, Juniper Networks announced multiple security vulnerabilities stemming from unauthorized code in ScreenOS, the operating system for their NetScreen VPN routers. The more sophisticated of these vulnerabilities was a passive VPN decryption capability, enabled by a change to one of the elliptic curve points used by the Dual EC pseudorandom number generator. In this paper, we describe the results of a full independent analysis of the ScreenOS randomness and VPN key establishment protocol subsystems, which we carried out in response to this incident. While Dual EC is known to be insecure against an attacker who can choose the elliptic curve parameters, Juniper had claimed in 2013 that ScreenOS included countermeasures against this type of attack. We find that, contrary to Juniper's public statements, the ScreenOS VPN implementation has been vulnerable since 2008 to passive exploitation by an attacker who selects the Dual EC curve point. This vulnerability arises due to apparent flaws in Juniper's countermeasures as well as a cluster of changes that were all introduced concurrently with the inclusion of Dual EC in a single 2008 release. We demonstrate the vulnerability on a real NetScreen device by modifying the firmware to install our own parameters, and we show that it is possible to passively decrypt an individual VPN session in isolation without observing any other network traffic. We investigate the possibility of passively fingerprinting ScreenOS implementations in the wild. This incident is an important example of how guidelines for random number generation, engineering, and validation can fail in practice.