We present a novel, computationally simple method of hiding any message in the stream of random bits by using a secret key. The method is called Bury Among Random Numbers (BARN). A stream of random bits is produced by extracting the entropy of a physical process in a hardware-based true random number generator (TRNG). The process of placing bits of a message into the stream of random bits is governed by the number of random bits skipped between subsequent insertions. The set of numbers that correspond to the steps of BARN is derived from a random number also provided by TRNG. Hence BARN cipher does not depend on any arithmetic function. We propose an effective method of computing random keys from a given number of random bits. We estimate the number of permutations that need to be tested during a brute-force attack on the new cipher for various key lengths. Some practical applications for the new class of symmetrical ciphers are discussed.
The conventional cryptography solutions are ill-suited to strict memory, size and power limitations of resource-constrained devices, so lightweight cryptography solutions have been specifically developed for this type of applications. In this domain of cryptography, the term lightweight never refers to inadequately low security, but rather to establishing the best balance to maintain sufficient security. This paper presents the first comprehensive survey evaluation of lightweight block ciphers in terms of their speed, cost, performance, and balanced efficiency in hardware implementation, and f…
This paper presents the hardware design and analysis of ACE and WAGE, two candidate ciphers for the NIST Lightweight Cryptography standardization. Both ciphers use sLiSCP's unified sponge duplex mode. ACE has an internal state of 320 bits, uses three 64 bit Simeck boxes, and implements both authenticated encryption and hashing. WAGE is based on the Welch-Gong stream cipher and provides authenticated encryption. WAGE has 259 bits of state, two 7 bit Welch-Gong permutations, and four lightweight 7 bit S-boxes. ACE and WAGE have the same external interface and follow the same I/O protocol to tran…
Security in embedded systems has become a main requirement in modern electronic devices. The demand for low-cost and highly secure cryptographic algorithms is increasingly growing in fields such as mobile telecommunications, handheld devices, etc. In this paper, we analyze and evaluate the development of cheap and relatively fast hardware implementations of the KATAN family of block ciphers. KATAN is a family of six hardware oriented block ciphers. All KATAN ciphers share an 80-bit key and have 32, 48, or 64-bit blocks. We use VHDL under Altera Quartus in conjunction with ModelSim to implement…
In this paper we will present various hardware architecture designs for implementing the SIMON 64/128 block cipher as a cryptographic component offering encryption, decryption and self-contained key-scheduling capabilities and discuss the issues and design options we encountered and the tradeoffs we made in implementing them. Finally, we will present the results of our hardware architectures' implementation performances on the Xilinx Spartan-6 FPGA series.
A common approach to protect confidential information is to use a stream cipher which combines plain text bits with a pseudo-random bit sequence. Among the existing stream ciphers, Non-Linear Feedback Shift Register (NLFSR)-based ones provide the best trade-off between cryptographic security and hardware efficiency. In this paper, we show how to further improve the hardware efficiency of Grain stream cipher. By transforming the NLFSR of Grain from its original Fibonacci configuration to the Galois configuration and by introducing a clock division block, we double the throughput of the 80 and 1…
Internet of Things connects lots of small constrained devices to the Internet. As in any other environment, communication security is important and cryptographic algorithms are one of many elements that we use in order to keep messages secure. Because of the constrained nature of these environments, it is necessary to use algorithms that do not require high computational power. Lightweight ciphers are therefore ideal candidates for this purpose. In this paper, we explore a possibility of attacking an ultra-lightweight cipher PRESENT by using a multiple fault attack. Utilizing the Differential …
This paper discusses mixing of chaotic systems as a dependable method for secure communication. Distribution of the entropy function for steady state as well as plaintext input sequences are analyzed. It is shown that the mixing of chaotic sequences results in a sequence that does not have any state dependence on the information encrypted by them. The generated output states of such a cipher approach the theoretical maximum for both complexity measures and cycle length. These features are then compared with some popular ciphers.
Most cryptosystems are defined over finite algebraic structures where arithmetic operations are performed modulo natural numbers. This applies to private key as well as to public key ciphers. No secure cryptosystems defined over the field of real numbers are known. In this work, we demonstrate the feasibility of constructing secure symmetric key ciphers defined over the field of real numbers. We consider the security of ciphers introduced in a previous work and based on solving linear and non-linear equations numerically. We complement the design of those ciphers to satisfy the requirements of…
We consider the problem of constructing an unconditionally secure cipher for the case when the key length is less than the length of the encrypted message. (Unconditional security means that a computationally unbounded adversary cannot obtain information about the encrypted message without the key.) In this article, we propose data compression and randomization techniques combined with entropically-secure encryption. The resulting cipher can be used for encryption in such a way that the key length does not depend on the entropy or the length of the encrypted message; instead, it is determined …
In 2002, Russell and Wang proposed a definition of entropically security that was developed within the framework of secret key cryptography. An entropically-secure system is unconditionally secure, that is, unbreakable, regardless of the enemy's computing power. In 2004, Dodis and Smith developed the results of Russell and Wang and, in particular, stated that the concept of an entropy-protected symmetric encryption scheme is extremely important for cryptography, since it is possible to construct entropy-protected symmetric encryption schemes with keys much shorter than the keys. the length of …
Lightweight stream ciphers are highly demanded in IoT applications. In order to optimize the hardware performance, a new class of stream cipher has been proposed. The basic idea is to employ a single Galois NLFSR with maximum period to construct the cipher. As a representative design of this kind of stream ciphers, Espresso is based on a 256-bit Galois NLFSR initialized by a 128-bit key. The $2^{256}-1$ maximum period is assured because the Galois NLFSR is transformed from a maximum length LFSR. However, we propose a Galois-to-Fibonacci transformation algorithm and successfully transform the G…
A new large class of $2^{100}$ possible stream ciphers as keystream generators KSGs, is presented. The sample cipher-structure-concept is based on randomly selecting a set of 16 maximum-period Nonlinear Feedback Shift Registers (NLFSRs). A non-linear combining function is merging the 16 selected sequences. All resulting stream ciphers with a total state-size of 223 bits are designed to result with the same security level and have a linear complexity exceeding $2^{81}$ and a period exceeding $2^{161}$. A Secret Unknown Cipher (SUC) is created randomly by selecting one cipher from that class of …
In this paper, we propose a novel fault attack termed as Single Event Transient Fault Analysis (SETFA) attack, which is well suited for hardware implementations. The proposed approach pinpoints hotspots in the cypher's Sbox combinational logic circuit that significantly reduce the key entropy when subjected to faults. ELEPHANT is a parallel authenticated encryption and associated data (AEAD) scheme targeted to hardware implementations, a finalist in the Lightweight cryptography (LWC) competition launched by NIST. In this work, we investigate vulnerabilities of ELEPHANT against fault analysis. …
Fault analysis is a powerful attack to stream ciphers. Up to now, the major idea of fault analysis is to simplify the cipher system by injecting some soft faults. We call it soft fault analysis. As a hardware-oriented stream cipher, Trivium is weak under soft fault analysis. In this paper we consider another type of fault analysis of stream cipher, which is to simplify the cipher system by injecting some hard faults. We call it hard fault analysis. We present the following results about such attack to Trivium. In Case 1 with the probability not smaller than 0.2396, the attacker can obtain 69 b…
One of the major open problems in symmetric cryptanalysis is to discover new specif i c types of invariant properties which can hold for a larger number of rounds of a block cipher. We have Generalised Linear Cryptanalysis (GLC) and Partitioning Cryptanalysis (PC). Due to double-exponential combinatorial explosion of the number of possible invariant properties systematic exploration is not possible and extremely few positive working examples of GLC are known. Our answer is to work with polynomial algebraic invariants which makes partitions more intelligible. We have developed a constructive al…
One of the key requirement of many schemes is that of random numbers. Sequence of random numbers are used at several stages of a standard cryptographic protocol. A simple example is of a Vernam cipher, where a string of random numbers is added to massage string to generate the encrypted code. It is represented as $C=M \oplus K $ where $M$ is the message, $K$ is the key and $C$ is the ciphertext. It has been mathematically shown that this simple scheme is unbreakable is key K as long as M and is used only once. For a good cryptosystem, the security of the cryptosystem is not be based on keeping…
Quality randomness is fundamental to cryptographic operations but on embedded systems good sources are (seemingly) hard to find. Rather than use expensive custom hardware, our ERHARD-RNG Pseudo-Random Number Generator (PRNG) utilizes entropy sources that are already common in a range of low-cost embedded platforms. We empirically evaluate the entropy provided by three sources---SRAM startup state, oscillator jitter, and device temperature---and integrate those sources into a full Pseudo-Random Number Generator implementation based on Fortuna. Our system addresses a number of fundamental challe…
Mageto, a random number generator based on one-dimensional cellular automaton (CA) is presented. Three procedures of secure implementation using Mageto is proposed and discussed. Implementations are very efficient in a wide range of hardware and software scenarios. It includes the advanced application of the Internet of Things (IoT) and cyber-physical systems which are both needed for computationally-efficient cryptographic primitives. Furthermore, the proposed primitive is inherently resistant against the Side Channel Attack (SCA), where many currently available ciphers, such as AES, require …
This paper shows that the Hirschfeld-Gebelein-Rényi maximal correlation between the message and the ciphertext provides good secrecy guarantees for cryptosystems that use short keys. We first establish a bound on the eavesdropper's advantage in guessing functions of the message in terms of maximal correlation and the Rényi entropy of the message. This result implies that maximal correlation is stronger than the notion of entropic security introduced by Russell and Wang. We then show that a small maximal correlation $ρ$ can be achieved via a randomly generated cipher with key length $\approx2\l…
In the case of the need of extraordinary security, Kirchhoff-loop-Johnson-(like)-noise ciphers can easily be integrated on existing types of digital chips in order to provide secure data communication between hardware processors, memory chips, hard disks and other units within a computer or other data processor system. The secure key exchange can take place at the very first run and the system can renew the key later at random times with an authenticated fashion to prohibit man-in-the-middle attack. The key can be stored in flash memories within the communicating chip units at hidden random ad…
Hardware Trojans (HTs) have drawn more and more attention in both academia and industry because of its significant potential threat. In this paper, we proposed a novel HT detection method using information entropy based clustering, named HTDet. The key insight of HTDet is that the Trojan usually be inserted in the regions with low controllability and low observability in order to maintain high concealment, which will result in that Trojan logics appear extremely low transitions during the simulation. This means that the logical regions with the low transitions will provide us with much more ab…
True random number generators (TRNGs) are essential components of cryptographic designs, which are used to generate private keys for encryption and authentication, and are used in masking countermeasures. In this work, we present a mechanism to design a stealthy parametric hardware Trojan for a ring oscillator based TRNG architecture proposed by Yang et al. at ISSCC 2014. Once the Trojan is triggered the malicious TRNG generates predictable non-random outputs. Such a Trojan does not require any additional logic (even a single gate) and is purely based on subtle manipulations on the sub-transis…
Cheap micro-controllers, such as the Arduino or other controllers based on the Atmel AVR CPUs are being deployed in a wide variety of projects, ranging from sensors networks to robotic submarines. In this paper, we investigate the feasibility of using the Arduino as a true random number generator (TRNG). The Arduino Reference Manual recommends using it to seed a pseudo random number generator (PRNG) due to its ability to read random atmospheric noise from its analog pins. This is an enticing application since true bits of entropy are hard to come by. Unfortunately, we show by statistical metho…
Good quality entropy sources are indispensable in most modern cryptographic protocols. Unfortunately, many currently deployed networked devices do not include them and may be vulnerable to Random Number Generator (RNG) attacks. Since most of these systems allow firmware upgrades and have serial communication facilities, the potential for retrofitting them with secure hardware-based entropy sources exists. To this aim, very low-cost, robust, easy to deploy solutions are required. Here, a retrofittable, sub 10$ entropy source based on chaotic dynamics is illustrated, capable of a 32 kbit/s rate …
EIM-TRNG: Obfuscating Deep Neural Network Weights with Encoding-in-Memory True Random Number Generator via RowHammer
Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, NJ, USA（电气与计算机工程系，新泽西理工学院，新泽西州诺威克）；Department of Computer Science, State University of New York at Binghamton, NY, USA（计算机科学系，纽约州立大学布法罗分校）
