The main focus of modern cryptanalysis is on breaking the implementation of cryptographic algorithms as opposed to traditional attacks which primarily target on mathematically breaking the algorithms. For over the last decade these new trend of attacks, Side Channel Attacks (SCAs), are becoming increasingly popular and pose a serious threat to cryptographic devices. Researchers proposing counte...

Hardware Trojans have gained high attention in academia, industry and by government agencies. The effective detection mechanisms and countermeasures against such malicious designs are only possible when there is a deep understanding of how hardware Trojans can be built in practice. In this work, we present a mechanism which shows how easily a stealthy hardware Trojan can be inserted in a provab...

First-order secure Threshold Implementations (TI) of symmetric cryptosystems provide provable security at a moderate overhead; yet attacks using higher-order statistical moments are still feasible. Cryptographic instances compliant to Higher-Order Threshold Implementation (HO-TI) can prevent such attacks, however, usually at unacceptable implementation costs. As an alternative concept we invest...

Recently two papers have been published on empirically measuring side-channel leakage in processors. The first paper introduced a framework for measuring side-channel leakage called “Side-Channel Vulnerability Factor” (SVF). SVF used phase correlation between victim and attacker programs to quantify leakage. A subsequent paper opposed some of the claims made in the SVF paper and introduced anot...

Quantum key distribution (QKD) offers the promise of absolutely secure communications. However, proofs of absolute security often assume perfect implementation from theory to experiment. Thus, existing systems may be prone to insidious side-channel attacks that rely on flaws in experimental implementation. Here we replace all real channels with virtual channels in a QKD protocol, making the rel...

The Problem of Side Channels A cryptographic mechanism based on algorithms which are proven to be secure may become vulnerable after it is implemented in some programming language and run on an actual computer system. Side channel attacks are based on the fact that by observing the implementation’s behavior which is not modeled by the underlying cryptographic algorithm the attacker can infer co...

We describe two new techniques of side-channel cryptanalysis which we call the impossible collision attack and the multiset collision attack. These are inspired by the state-of-the-art cryptanalytic techniques of impossible differential attacks [BBS99] and partial-function collision attacks [GM00] respectively. Using these techniques on an example of the AES we show that one has to mask all the...

This work1 provides a detailed study of two finalists of the SHA-3 competition from the sidechannel analysis point of view. For both functions when used as a MAC, this paper presents detected strategies for performing a power analysis. Besides the classical HMAC mode, two additionally proposed constructions, the envelope MAC for Grøstl and the Skein-MAC for Skein, are analyzed. Consequently, ex...

A block cipher encrypts data one block at a time. For bulk data encryption, a block cipher is usually used in a mode of operation. Cipher Block Chaining (CBC) mode encryption is one of the most commonly used modes of operation. The security properties of CBC mode encryption have been studied extensively. One well-known attack against CBC mode encryption allows an attacker, with some restriction...

Based on re-keying techniques by Abdalla, Bellare, and Borst, we consider two black-box secure block cipher based symmetric encryption schemes, which we prove secure in the physically observable cryptography model. They are proven side-channel secure against a strong type of adversary that can adaptively choose the leakage function as long as the leaked information is bounded. It turns out that...