A new TRNG based on coherent sampling with self-timed rings

Random numbers play a key role in applications such as industrial simulations, laboratory experimentation, computer games, and engineering problem solving. The design of new true random generators (TRNGs) has attracted the attention of the research community for many years. Designs with little hardware requirements and high throughput are demanded by new and powerful applications. In this paper, we introduce the design of a novel TRNG based on the coherent sampling (CS) phenomenon. Contrary to most designs based on this phenomenon, ours uses self-timed rings (STRs) instead of the commonly employed ring oscillators (ROs). Our design has two key advantages over existing proposals based on CS. It does not depend on the FPGA vendor used and does not need manual placement and routing in the manufacturing process, resulting in a highly portable generator. Our experiments show that the TRNG offers a very high throughput with a moderate cost in hardware. The results obtained with ENT, DIEHARD, and National Institute of Standards and Technology (NIST) statistical test suites evidence that the output bitstream behaves as a truly random variable.This work was supported in part by the Ministerio de Economia y Competitividad (MINECO), Security and Privacy in the Internet of You (SPINY), under Grant TIN2013-46469-R, and in part by the Comunidad de Madrid (CAM), Cybersecurity, Data, and Risks (CIBERDINE), underGrant S2013/ICE-3095

FPGA Based Random Number Generation for Cryptographic Applications

Random numbers are useful for a variety of purposes, such as generating data encryption keys,simulating and modeling complex phenomena and for selecting random samples from larger data sets. They have also been used aesthetically, for example in literature and music, and are of course ever popular for games and gambling. When discussing single numbers, a random number is one that is drawn from a set of possible values, each of which is equally probable, i.e., a uniform distribution. When discussing a sequence of random numbers, each number drawn must be statistically independent of the others. Random numbers are generated by various methods. The two types of generators used for random number generation are pseudo random number generator (PRNG) and true random number generator (TRNG). The numbers generated are random because no polynomial – time algorithm can describe the relation amongst the different numbers of the sequence. Numbers generated by true random number generator (TRNG) or cryptographically secure pseudo random number generator (CSPRNG). The sources of randomness in TRNG are physical phenomena like lightning, radioactive decay, thermal noise etc. The source of randomness in CSPRNG is the algorithm on which it is based. In this project, the random numbers generated for cryptographic applications were generated by using the Blum Blum Shub generator, the CSPRBG. It was implemented on a FPGA platform using VHDL programming language and the simulation was done and tested on the Xilinx ISE 10.1i

RSA Power Analysis Obfuscation: A Dynamic FPGA Architecture

The modular exponentiation operation used in popular public key encryption schemes, such as RSA, has been the focus of many side channel analysis (SCA) attacks in recent years. Current SCA attack countermeasures are largely static. Given sufficient signal-to-noise ratio and a number of power traces, static countermeasures can be defeated, as they merely attempt to hide the power consumption of the system under attack. This research develops a dynamic countermeasure which constantly varies the timing and power consumption of each operation, making correlation between traces more difficult than for static countermeasures. By randomizing the radix of encoding for Booth multiplication and randomizing the window size in exponentiation, this research produces a SCA countermeasure capable of increasing RSA SCA attack protection

Optical quantum random number generation: applications of single-photon event timing

This dissertation is the result of research which, although electrical and computer engineering in nature, also aims to improve the performance of many systems in the field of quantum information. For example, random number generators are used in almost all areas of science, and the initial portion of this work details the theory, design, and characterization of two photon-arrival-time quantum random number generators (QRNGs). After the QRNGs were completed, it was realized that their performance was severely limited both by the maximum detection rate of the single-photon detectors used, and the precision at which the arrival times could be resolved. The single-photon detectors used for both QRNGs are single-photon avalanche photodiodes (SPADs), devices which when operated below their breakdown voltage can create a macroscopic amount of current (an avalanche) in response to a single incident photon. Some of this charge can become trapped in defects or impurities; if this trapped charge is released when the SPAD is active, a secondary ‘false’ detection event, or ‘afterpulse’ can occur. To lower the afterpulse probability to reasonable levels (< 1%), we attempted to reduce the amount of avalanche charge by halting its growth promptly with high-speed electronics, so that defects have a lower probability of becoming populated in the first place. Initial results show reductions in afterpulse probability by up to a factor of 12, corresponding to a ~20% decrease in dead time, a value that could be improved further. We developed an FPGA-based time-to-digital converter system for use specifically with SPADs, achieving a time-bin resolution of 100 ps, with lower dead time and higher maximum detection rate than all currently available detection systems. This further allowed for the creation of a new higher-order SPAD characterization technique, which was identified previously unknown subtleties to SPAD operation. Finally, we developed an ultra-low-latency QRNG, which was used in one of the recent loophole-free demonstrations of quantum nonlocality. The final latency was below 2.5 ns, to our knowledge the lowest latency QRNG to date. Of special interest, however, is our subsequent exploration into the characterization of its bit-probability drift using atomic clock stability techniques. By employing the Allan deviation and implementing precision feedback, the additional frequency drift caused by environmental fluctuations is reduced such that the resulting bit stream can pass cryptographic random number tests for sample sizes up to 5 Gb. This system is currently intended for the NIST random-number beacon, a world-wide trusted source of random bits

All-Silicon-Based Photonic Quantum Random Number Generators

Random numbers are fundamental elements in different fields of science and technology such as computer simulation like Monte Carlo-method simulation, statistical sampling, cryptography, games and gambling, and other areas where unpredictable results are necessary. Random number generators (RNG) are generally classified as “pseudo”-random number generators (PRNG) and "truly" random number generators (TRNG). Pseudo random numbers are generated by computer algorithms with a (random) seed and a specific formula. The random numbers produced in this way (with a small degree of unpredictability) are good enough for some applications such as computer simulation. However, for some other applications like cryptography they are not completely reliable. When the seed is revealed, the entire sequence of numbers can be produced. The periodicity is also an undesirable property of PRNGs that can be disregarded for most practical purposes if the sequence recurs after a very long period. However, the predictability still remains a tremendous disadvantage of this type of generators. Truly random numbers, on the other hand, can be generated through physical sources of randomness like flipping a coin. However, the approaches exploiting classical motion and classical physics to generate random numbers possess a deterministic nature that is transferred to the generated random numbers. The best solution is to benefit from the assets of indeterminacy and randomness in quantum physics. Based on the quantum theory, the properties of a particle cannot be determined with arbitrary precision until a measurement is carried out. The result of a measurement, therefore, remains unpredictable and random. Optical phenomena including photons as the quanta of light have various random, non-deterministic properties. These properties include the polarization of the photons, the exact number of photons impinging a detector and the photon arrival times. Such intrinsically random properties can be exploited to generate truly random numbers. Silicon (Si) is considered as an interesting material in integrated optics. Microelectronic chips made from Si are cheap and easy to mass-fabricate, and can be densely integrated. Si integrated optical chips, that can generate, modulate, process and detect light signals, exploit the benefits of Si while also being fully compatible with electronic. Since many electronic components can be integrated into a single chip, Si is an ideal candidate for the production of small, powerful devices. By complementary metal-oxide-semiconductor (CMOS) technology, the fabrication of compact and mass manufacturable devices with integrated components on the Si platform is achievable. In this thesis we aim to model, study and fabricate a compact photonic quantum random number generator (QRNG) on the Si platform that is able to generate high quality, "truly" random numbers. The proposed QRNG is based on a Si light source (LED) coupled with a Si single photon avalanche diode (SPAD) or an array of SPADs which is called Si photomultiplier (SiPM). Various implementations of QRNG have been developed reaching an ultimate geometry where both the source and the SPAD are integrated on the same chip and fabricated by the same process. This activity was performed within the project SiQuro—on Si chip quantum optics for quantum computing and secure communications—which aims to bring the quantum world into integrated photonics. By using the same successful paradigm of microelectronics—the study and design of very small electronic devices typically made from semiconductor materials—, the vision is to have low cost and mass manufacturable integrated quantum photonic circuits for a variety of different applications in quantum computing, measure, sensing, secure communications and services. The Si platform permits, in a natural way, the integration of quantum photonics with electronics. Two methodologies are presented to generate random numbers: one is based on photon counting measurements and another one is based on photon arrival time measurements. The latter is robust, masks all the drawbacks of afterpulsing, dead time and jitter of the Si SPAD and is effectively insensitive to ageing of the LED and to its emission drifts related to temperature variations. The raw data pass all the statistical tests in national institute of standards and technology (NIST) tests suite and TestU01 Alphabit battery without a post processing algorithm. The maximum demonstrated bit rate is 1.68 Mbps with the efficiency of 4-bits per detected photon. In order to realize a small, portable QRNG, we have produced a compact configuration consisting of a Si nanocrystals (Si-NCs) LED and a SiPM. All the statistical test in the NIST tests suite pass for the raw data with the maximum bit rate of 0.5 Mbps. We also prepared and studied a compact chip consisting of a Si-NCs LED and an array of detectors. An integrated chip, composed of Si p+/n junction working in avalanche region and a Si SPAD, was produced as well. High quality random numbers are produced through our robust methodology at the highest speed of 100 kcps. Integration of the source of entropy and the detector on a single chip is an efficient way to produce a compact RNG. A small RNG is an essential element to guarantee the security of our everyday life. It can be readily implemented into electronic devices for data encryption. The idea of "utmost security" would no longer be limited to particular organs owning sensitive information. It would be accessible to every one in everyday life

Stochastic Memory Devices for Security and Computing

With the widespread use of mobile computing and internet of things, secured communication and chip authentication have become extremely important. Hardware-based security concepts generally provide the best performance in terms of a good standard of security, low power consumption, and large-area density. In these concepts, the stochastic properties of nanoscale devices, such as the physical and geometrical variations of the process, are harnessed for true random number generators (TRNGs) and physical unclonable functions (PUFs). Emerging memory devices, such as resistive-switching memory (RRAM), phase-change memory (PCM), and spin-transfer torque magnetic memory (STT-MRAM), rely on a unique combination of physical mechanisms for transport and switching, thus appear to be an ideal source of entropy for TRNGs and PUFs. An overview of stochastic phenomena in memory devices and their use for developing security and computing primitives is provided. First, a broad classification of methods to generate true random numbers via the stochastic properties of nanoscale devices is presented. Then, practical implementations of stochastic TRNGs, such as hardware security and stochastic computing, are shown. Finally, future challenges to stochastic memory development are discussed