Fault Attack on ACORN v3

Fault attack is one of the most efficient side channel attacks and has attracted much attention in recent public cryptographic literatures. In this work we introduce a fault attack on the authenticated cipher ACORN v3. Our attack is done under the assumption that a fault is injected into an initial state of ACORN v3 randomly, and contains two main steps: fault locating and equation solving. At the first step, we introduce concepts of unique set and non-unique set, where differential strings belonging to unique sets can determine the fault location uniquely. For strings belonging to non-unique sets, we use some strategies to increase the probability of determining the fault location uniquely to almost 1. At the second step, we demonstrate several ways of retrieving equations, and then obtain the initial state by solving equations with the guess-and-determine method. With $n$ fault experiments, we can recover the initial state with time complexity $c \cdot2^{146.5-3.52\cdot n}$, where $c$ is the time complexity of solving linear equations and $26<n<43$. We also apply the attack to ACORN v2, which shows that, comparing with ACORN v2, the tweaked version ACORN v3 is more vulnerable against the fault attack

Breaking ACORN with a Single Fault

Assuring security of the Internet of Things (IoT) is much more challenging than assuring security of centralized environments, like the cloud. A reason for this is that IoT devices are often deployed in domains that are remotely managed and monitored. Thus, their physical security cannot be guaranteed as reliably as physical security of data centers. Some believe that physical security becomes less important if all data processed and stored within a device is encrypted. However, an attacker with a physical access to a device implementing an encryption algorithm may be able to extract the encryption key and decrypt data. As a demonstration, in this paper we attack ACORN stream cipher, a finalist of CESAR competition for authenticated encryption. By injecting a single stuck-at-0 fault into ACORN\u27s implementation, we reduce its non-linear feedback function to a linear one. Since this obviously makes ACORN weaker, many known attacks can be applied to break it. We apply an algebraic attack which recovers the key from $2^{15.34}$ keystream bits using $2^{35.46}$ operations

Masking the Lightweight Authenticated Ciphers ACORN and Ascon in Software

The ongoing CAESAR competition aims at finding authenticated encryption schemes that offer advantages over AES-GCM for several use-cases, including lightweight applications. ACORN and Ascon are the two finalists for this profile. Our paper compares these two candidates according to their resilience against differential power analysis and their ability to integrate countermeasures against such attacks. Especially, we focus on software implementations and provide benchmarks for several security levels on an ARM Cortex-M3 embedded microprocessor

Fault Attacks In Symmetric Key Cryptosystems

Fault attacks are among the well-studied topics in the area of cryptography. These attacks constitute a powerful tool to recover the secret key used in the encryption process. Fault attacks work by forcing a device to work under non-ideal environmental conditions (such as high temperature) or external disturbances (such as glitch in the power supply) while performing a cryptographic operation. The recent trend shows that the amount of research in this direction; which ranges from attacking a particular primitive, proposing a fault countermeasure, to attacking countermeasures; has grown up substantially and going to stay as an active research interest for a foreseeable future. Hence, it becomes apparent to have a comprehensive yet compact study of the (major) works. This work, which covers a wide spectrum in the present day research on fault attacks that fall under the purview of the symmetric key cryptography, aims at fulfilling the absence of an up-to-date survey. We present mostly all aspects of the topic in a way which is not only understandable for a non-expert reader, but also helpful for an expert as a reference

Electromagnetic Side-Channel Resilience against Lightweight Cryptography

Side-channel attacks are an unpredictable risk factor in cryptography. Therefore, observations of leakages through physical parameters, i.e., power and electromagnetic (EM) radiation, etc., of digital devices are essential to minimise vulnerabilities associated with cryptographic functions. Compared to costs in the past, performing side-channel attacks using inexpensive test equipment is becoming a reality. Internet-of-Things (IoT) devices are resource-constrained, and lightweight cryptography is a novel approach in progress towards IoT security. Thus, it would provide sufficient data and privacy protection in such a constrained ecosystem. Therefore, cryptanalysis of physical leakages regarding these emerging ciphers is crucial. EM side-channel attacks seem to cause a significant impact on digital forensics nowadays. Within existing literature, power analysis seems to have considerable attention in research whereas other phenomena, such as EM, should continue to be appropriately evaluated in playing a role in forensic analysis.The emphasis of this thesis is on lightweight cryptanalysis. The preliminary investigations showed no Correlation EManalysis (CEMA) of PRESENT lightweight algorithm. The PRESENT is a block cipher that promises to be adequate for IoT devices, and is expected to be used commercially in the future. In an effort to fill in this research gap, this work examines the capabilities of a correlation EM side-channel attack against the PRESENT. For that, Substitution box (S-box) of the PRESENT was targeted for its 1st round with the use of a minimum number of EM waveforms compared to other work in literature, which was 256. The attack indicates the possibility of retrieving 8 bytes of the secret key out of 10 bytes. The experimental process started from a Simple EMA (SEMA) and gradually enhanced up to a CEMA. The thesis presents the methodology of the attack modelling and the observations followed by a critical analysis. Also, a technical review of the IoT technology and a comprehensive literature review on lightweight cryptology are included