There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

1. The Advanced Encryption Standard Process.- 2. Preliminaries.- 3. Specification of Rijndael.- 4. Implementation Aspects.- 5. Design Philosophy.- 6. The Data Encryption Standard.- 7. Correlation Matrices.- 8. Difference Propagation.- 9. The Wide Trail Strategy.- 10. Cryptanalysis.- 11. Related Block Ciphers.- Appendices.- A. Propagation Analysis in Galois Fields.- A.1.1 Difference Propagation.- A.l.2 Correlation.- A. 1.4 Functions that are Linear over GF(2).- A.2.1 Difference Propagation.- A.2.2 Correlation.- A.2.4 Functions that are Linear over GF(2).- A.3.3 Dual Bases.- A.4.2 Relationship Between Trace Patterns and Selection Patterns.- A.4.4 Illustration.- A.5 Rijndael-GF.- B. Trail Clustering.- B.1 Transformations with Maximum Branch Number.- B.2 Bounds for Two Rounds.- B.2.1 Difference Propagation.- B.2.2 Correlation.- B.3 Bounds for Four Rounds.- B.4 Two Case Studies.- B.4.1 Differential Trails.- B.4.2 Linear Trails.- C. Substitution Tables.- C.1 SRD.- C.2 Other Tables.- C.2.1 xtime.- C.2.2 Round Constants.- D. Test Vectors.- D.1 KeyExpansion.- D.2 Rijndael(128,128).- D.3 Other Block Lengths and Key Lengths.- E. Reference Code.

The Design of Rijndael: AES - The Advanced Encryption Standard

After two decades of research and development, elliptic curve cryptography now has widespread exposure and acceptance. Industry, banking, and government standards are in place to facilitate extensive deployment of this efficient public-key mechanism. Anchored by a comprehensive treatment of the practical aspects of elliptic curve cryptography (ECC), this guide explains the basic mathematics, describes state-of-the-art implementation methods, and presents standardized protocols for public-key encryption, digital signatures, and key establishment. In addition, the book addresses some issues that arise in software and hardware implementation, as well as side-channel attacks and countermeasures. Readers receive the theoretical fundamentals as an underpinning for a wealth of practical and accessible knowledge about efficient application. Features & Benefits: * Breadth of coverage and unified, integrated approach to elliptic curve cryptosystems * Describes important industry and government protocols, such as the FIPS 186-2 standard from the U.S. National Institute for Standards and Technology * Provides full exposition on techniques for efficiently implementing finite-field and elliptic curve arithmetic* Distills complex mathematics and algorithms for easy understanding* Includes useful literature references, a list of algorithms, and appendices on sample parameters, ECC standards, and software toolsThis comprehensive, highly focused reference is a useful and indispensable resource for practitioners, professionals, or researchers in computer science, computer engineering, network design, and network data security.

https://cdn.preterhuman.net/texts/cryptography/Hankerson,%20Menezes,%20Vanstone.%20Guide%20to%20elliptic%20curve%20cryptography%20(Springer,%202004)(ISBN%20038795273X)(332s)_CsCr_.pdf

Guide to Elliptic Curve Cryptography

National Institute of Standards and Technology における超伝導研究及び生活

The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

Many side-channel attacks on implementations of cryptographic algorithms have been developed in recent years demonstrating the ease of extracting the secret key. In response, various schemes to protect cryptographic devices against such attacks have been devised and some implemented in practice. Almost all of these protection schemes target an individual side-channel attack and consequently, it is not obvious whether a scheme for protecting the device against one type of sidechannel attacks may make the device more vulnerable to another type of side-channel attacks. We examine in this paper the possibility of such a negative impact for the case where fault detection circuitry is added to a device (to protect it against fault injection attacks) and analyze the resistance of the modified device to power attacks. To simplify the analysis we focus on only one component in the cryptographic device (namely, the S-box in the AES and Kasumi ciphers), and perform power attacks on the original implementation and on a modified implementation with an added parity check circuit. Our results show that the presence of the parity check circuitry has a negative impact on the resistance of the device to power analysis attacks.

PowerAttacksResistanceofCryptographicS-boxeswithaddedError DetectionCircuits

Through the prevalence of interconnected embedded systems, the vision of pervasive computing has become reality over the last few years. More recently, this evolutionary development has become better known as the Internet of Things. As part of this development, embedded security has become an increasingly important issue in a multitude of applications. Examples include the Stuxnet virus, which has allegedly delayed the Iranian nuclear program, killer applications in the consumer area like iTunes or Amazon's Kindle (the business models of which rely on IP protection) and even medical implants like pace makers and insulin pumps that allow remote configuration. These examples show the destructive and constructive aspects of modern embedded security. In this tutorial we will address both the constructive and "penetration testing" aspect of embedded security.In the area of destructive embedded security implementation attacks, also known as physical attacks, are of crucial importance. Whereas a network-borne attacker usually can't exploit the physical environment of an application, embedded devices often allow this. For instance, an attacker can monitor the power or timing behavior of a device. Also she can force the device to malfunction, e.g., through power spikes, and deduct information from faulty outputs. Many systems which are otherwise secure become vulnerable against implementation attacks. In this talk, we will focus on side-channel attacks, or SCA, which form arguably the most powerful method among physical attacks. After developing the mechanics of DPA (differential power analysis), we will look at recent case studies in which real-world implementation were broken using SCA. This includes successful attacks against contactless smart cards and FPGAs.With respect to constructive aspects of embedded security, we will look at the field of lightweight cryptography. The goal here is to provide security at the lowest possible "cost", e.g., measured in power consumption, code size or chip area. Over the last six years or so, this has become a very active area within symmetric cryptography. Very recently, even NSA released two lightweight ciphers, SIMON and SPECK. We will look at the motiviation for such ciphers, e.g., for passive RFID tags or anti-counterfeiting applications. We will then introduce several lightweight constructions and will compare them with AES.

Constructive and destructive aspects of embedded security in the internet of things

Die Zukunft der Elektromobilitat wird derzeit an vielen Fronten entschieden. Doch neben der eingeschrankten Reichweite und den hohen Kosten bereitet den Entwicklern vor allem die IT-Sicherheit einer kunftigen Infrastruktur grose Sorgen. Die Gefahr eines Missbrauchs an einzelnen Fahrzeugen bis hin zu Systemausfallen der verbundenen Infrastruktur soll deshalb das neu gegrundete Konsortium „Secure eMobility“ minimieren.

IT-Sicherheit in der Elektromobilität

Channel Reciprocity-based Key Generation (CRKG) exploits reciprocal channel randomness to establish shared secret keys between wireless terminals. This new security technique is expected to complement existing cryptographic techniques for secret key distribution of future wireless networks. In this paper, we present a new attack, reconfigurable intelligent surface (RIS) jamming, and show that an attacker can prevent legitimate users from agreeing on the same key by deploying a malicious RIS to break channel reciprocity. Specifically, we elaborate on three examples to implement the RIS jamming attack: Using active nonreciprocal circuits, performing time-varying controls, and reducing the signal-to-noise ratio. The attack effect is then studied by formulating the secret key rate with a relationship to the deployment of RIS. To resist such RIS jamming attacks, we propose a countermeasure that exploits wideband signals for multipath separation. The malicious RIS path is distinguished from all separated channel paths, and thus the countermeasure is referred to as contaminated path removal-based CRKG(CRP-CRKG). We present simulation results, showing that legitimate users under RIS jamming are still able to generate secret keys from the remaining paths. We also experimentally demonstrate the RIS jamming attack by using commodity Wi-Fi devices in conjunction with a fabricated RIS prototype. In our experiments, we were able to increase the average bit disagreement ratio (BDR) of raw secret keys by 20%. Further, we successfully demonstrate the proposed CRP-CRKG countermeasure to tackle RIS jamming in wideband systems as long as the source of randomness and the RIS propagation paths are separable.

Christof Paar

Papers

PowerAttacksResistanceofCryptographicS-boxeswithaddedError DetectionCircuits

Constructive and destructive aspects of embedded security in the internet of things

IT-Sicherheit in der Elektromobilität

RIS-Jamming: Breaking Key Consistency in Channel Reciprocity-based Key Generation

Trusted Computing in Automotive Systems