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」

An efficient identity-based blind signature scheme without bilinear pairings

The block cipher is one of the most important primitives in modern cryptography, information and network security; one of the primary purposes of such ciphers is to provide confidentiality for data transmitted in insecure communication environments. To ensure that confidentiality is robustly provided, it is essential to investigate the security of a block cipher against a variety of cryptanalytic attacks. In this thesis, we propose a new extension of differential cryptanalysis, which we call the impossible boomerang attack. We describe the early abort technique for (related-key) impossible differential cryptanalysis and rectangle attacks. Finally, we analyse the security of a number of block ciphers that are currently being widely used or have recently been proposed for use in emerging cryptographic applications; our main cryptanalytic results are as follows. • An impossible differential attack on 7-round AES when used with 128 or 192 key bits, and an impossible differential attack on 8-round AES when used with 256 key bits. An impossible boomerang attack on 6-round AES when used with 128 key bits, and an impossible boomerang attack on 7-round AES when used with 192 or 256 key bits. A related-key impossible boomerang attack on 8-round AES when used with 192 key bits, and a related-key impossible boomerang attack on 9-round AES when used with 256 key bits, both using two keys. • An impossible differential attack on 11-round reduced Camellia when used with 128 key bits, an impossible differential attack on 12-round reduced Camellia when used with 192 key bits, and an impossible differential attack on 13-round reduced Camellia when used with 256 key bits. • A related-key rectangle attack on the full Cobra-F64a, and a related-key differential attack on the full Cobra-F64b. • A related-key rectangle attack on 44-round SHACAL-2. • A related-key rectangle attack on 36-round XTEA. • An impossible differential attack on 25-round reduced HIGHT, a related-key rectangle attack on 26-round reduced HIGHT, and a related-key impossible differential attack on 28-round reduced HIGHT.

/pdf/cryptanalysis-of-block-ciphers-re93nubuom.pdf

Cryptanalysis of Block Ciphers

Advanced bit manipulation operations are not efficiently supported by commodity word-oriented microprocessors. Programming tricks are typically devised to shorten the long sequence of instructions needed to emulate these complicated bit operations. As these bit manipulation operations are relevant to applications that are becoming increasingly important, we propose direct support for them in microprocessors. In particular, we propose fast bit gather (or parallel extract), bit scatter (or parallel deposit) and bit permutation instructions (including group, butterfly and inverse butterfly). We show that all these instructions can be implemented efficiently using both the fast butterfly and inverse butterfly network datapaths. Specifically, we show that parallel deposit can be mapped onto a butterfly circuit and parallel extract can be mapped onto an inverse butterfly circuit. We define static, dynamic and loop invariant versions of the instructions, with static versions utilizing a much simpler functional unit. We show how a hardware decoder can be implemented for the dynamic and loop-invariant versions to generate, dynamically, the control signals for the butterfly and inverse butterfly datapaths. The simplest functional unit we propose is smaller and faster than an ALU. We also show that these instructions yield significant speedups over a basic RISC architecture for a variety of different application kernels taken from applications domains including bioinformatics, steganography, coding, compression and random number generation.

/pdf/fast-bit-gather-bit-scatter-and-bit-permutation-instructions-19sbjn4lga.pdf

Fast Bit Gather, Bit Scatter and Bit Permutation Instructions for Commodity Microprocessors

Using Russian digital signature (DS) standards as the underlying scheme there are designed the blind DS protocols that are the first known implementation of the blind DS based on signature standards. There are also proposed blind collective DS protocols based on the DS standards. The last protocols are also the first implementation of the blind multi-signature schemes using the signature verification equations specified by DS standards.

/pdf/blind-signature-protocols-from-digital-signature-standards-24ge79tiqa.pdf

Blind Signature Protocols from Digital Signature Standards

Using Schnorr’s digital signature (DS) scheme as the underlying scheme there is designed the collective DS protocol. In the proposed collective DS protocol the signature is formed simultaneously by all signers, therefore using this protocol leads to natural solution of the problem of signing simultaneously a contract. Using the proposed collective DS protocol the blind collective DS protocol has been designed, which is a new type of the multi-signature schemes. For simultaneous signing a package of different contracts by different sets of signers it is proposed another new multi-signature scheme called composite signature.

/pdf/blind-collective-signature-protocol-based-on-discrete-4mjxv8xkki.pdf

Blind Collective Signature Protocol Based on Discrete Logarithm Problem.

Performed security estimation has shown that twelve-round cipher SPECTR-H64 is secure against differential attack and the extension box is a critical element of this cipher. A modified eight-round version SPECTR-H64 + is proposed.

Fast Ciphers for Cheap Hardware: Differential Analysis of SPECTR-H64

This work focuses the problem of increasing the integral implementation efficacy of block ciphers. It proposes a new approach to the cipher design, suitable to applications, where constrained resources are available to embedded security mechanisms, such as ad-hoc, sensor and wireless networks. The paper develops the cipher design approach based on the use of data-dependent (DD) operations (DDOs). A new class of DDO based on the advanced controlled elements (CEs) is introduced, which is proven well suited to hardware implementations, for ASIC and FPGA devices. Classification of the CEs and properties of some new DDOs are also presented. A new DDO-based cipher design is considered, which is more efficient for VLSI implementation than AES finalists and other known DDO-based ciphers. For the proposed cipher, Eagle-128, both ASIC and FPGA implementation results are presented. Finally comparisons with other published implementations are illustrated, using the Performance/Cost ratio and Performance/(Cost*Frequency) ratio indices.

/pdf/new-class-of-cryptographic-primitives-and-cipher-design-for-3f26b1r3tp.pdf

New Class of Cryptographic Primitives and Cipher Design for Networks Security.

Recently, Data Dependent Permutations (DDP) have attracted the interest of cryptographers and ciphers designers. SPECTR-H64 and CIKS-1 are latest published powerful encryption algorithms, based on DDP transformations. In this paper, the implementation cost in different hardware devices (FPGA and ASIC) for DDP is introduced. In addition, the performance of these data transformation components is presented. Detailed analysis is shown, in terms of covered area, frequency, and throughput for DDP VLSI integration. Furthermore, two different architectures for hardware implementation of CIKS-1 and SPECTR-H64 are proposed. The first, based on full rolling technique minimizes the area resources. The second uses a pipelined development design and has high-speed performance. Both architectures have been implemented in FPGA and ASIC devices.

Encryption and Data Dependent Permutations: Implementation Cost and Performance Evaluation

New options of the hidden discrete logarithm problem are proposed as cryptographic primitive of the post-quantum signature algorithms. Two signature schemes using computations in finite non-commutative algebras with associative multiplication operation are introduced. The main feature of the proposed signature algorithms consists in using locally invertible elements of algebras. Two different types of algebras are used: i) containing global bi-side unit and ii) containing a large set of global right-side units.

Alexander A. Moldovyan

Papers

Blind Collective Signature Protocol Based on Discrete Logarithm Problem.

Fast Ciphers for Cheap Hardware: Differential Analysis of SPECTR-H64

New Class of Cryptographic Primitives and Cipher Design for Networks Security.

Encryption and Data Dependent Permutations: Implementation Cost and Performance Evaluation

Post-quantum signature algorithms based on the hidden discrete logarithm problem.