We present a new tweakable block cipher family SKINNY, whose goal is to compete with NSA recent design SIMON in terms of hardware/software performances, while proving in addition much stronger security guarantees with regards to differential/linear attacks. In particular, unlike SIMON, we are able to provide strong bounds for all versions, and not only in the single-key model, but also in the related-key or related-tweak model. SKINNY has flexible block/key/tweak sizes and can also benefit from very efficient threshold implementations for side-channel protection. Regarding performances, it outperforms all known ciphers for ASIC round-based implementations, while still reaching an extremely small area for serial implementations and a very good efficiency for software and micro-controllers implementations SKINNY has the smallest total number of AND/OR/XOR gates used for encryption process.

Secondly, we present MANTIS, a dedicated variant of SKINNY for low-latency implementations, that constitutes a very efficient solution to the problem of designing a tweakable block cipher for memory encryption. MANTIS basically reuses well understood, previously studied, known components. Yet, by putting those components together in a new fashion, we obtain a competitive cipher to PRINCE in latency and area, while being enhanced with a tweak input.

/pdf/the-skinny-family-of-block-ciphers-and-its-low-latency-12yjnnzi8w.pdf

The SKINNY Family of Block Ciphers and Its Low-Latency Variant MANTIS

In the past few years, lightweight cryptography has become a popular research discipline with a number of ciphers and hash functions proposed. The designers' focus has been predominantly to minimize the hardware area, while other goals such as low latency have been addressed rather recently only. However, the optimization goal of low energy for block cipher design has not been explicitly addressed so far. At the same time, it is a crucial measure of goodness for an algorithm. Indeed, a cipher optimized with respect to energy has wide applications, especially in constrained environments running on a tight power/energy budget such as medical implants.

This paper presents the block cipher Midorii¾?The name of the cipher is the Japanese translation for the word Green. that is optimized with respect to the energy consumed by the circuit per bt in encryption or decryption operation. We deliberate on the design choices that lead to low energy consumption in an electrical circuit, and try to optimize each component of the circuit as well as its entire architecture for energy. An added motivation is to make both encryption and decryption functionalities available by small tweak in the circuit that would not incur significant area or energy overheads. We propose two energy-efficient block ciphers Midori128i¾?and Midori64i¾?with block sizes equal to 128 and 64 bits respectively. These ciphers have the added property that a circuit that provides both the functionalities of encryption and decryption can be designed with very little overhead in terms of area and energy. We compare our results with other ciphers with similar characteristics: it was found that the energy consumptions ofi¾?Midori64i¾? and Midori128i¾? are by far better when compared ciphers like PRINCE and NOEKEON.

/pdf/midori-a-block-cipher-for-low-energy-1zpmlxg3mn.pdf

Midori: A Block Cipher for Low Energy

Cryptosystems I.- On Ideal Lattices and Learning with Errors over Rings.- Fully Homomorphic Encryption over the Integers.- Converting Pairing-Based Cryptosystems from Composite-Order Groups to Prime-Order Groups.- Fully Secure Functional Encryption: Attribute-Based Encryption and (Hierarchical) Inner Product Encryption.- Obfuscation and Side Channel Security.- Secure Obfuscation for Encrypted Signatures.- Public-Key Encryption in the Bounded-Retrieval Model.- Protecting Circuits from Leakage: the Computationally-Bounded and Noisy Cases.- 2-Party Protocols.- Partial Fairness in Secure Two-Party Computation.- Secure Message Transmission with Small Public Discussion.- On the Impossibility of Three-Move Blind Signature Schemes.- Efficient Device-Independent Quantum Key Distribution.- Cryptanalysis.- New Generic Algorithms for Hard Knapsacks.- Lattice Enumeration Using Extreme Pruning.- Algebraic Cryptanalysis of McEliece Variants with Compact Keys.- Key Recovery Attacks of Practical Complexity on AES-256 Variants with up to 10 Rounds.- IACR Distinguished Lecture.- Cryptography between Wonderland and Underland.- Automated Tools and Formal Methods.- Automatic Search for Related-Key Differential Characteristics in Byte-Oriented Block Ciphers: Application to AES, Camellia, Khazad and Others.- Plaintext-Dependent Decryption: A Formal Security Treatment of SSH-CTR.- Computational Soundness, Co-induction, and Encryption Cycles.- Models and Proofs.- Encryption Schemes Secure against Chosen-Ciphertext Selective Opening Attacks.- Cryptographic Agility and Its Relation to Circular Encryption.- Bounded Key-Dependent Message Security.- Multiparty Protocols.- Perfectly Secure Multiparty Computation and the Computational Overhead of Cryptography.- Adaptively Secure Broadcast.- Universally Composable Quantum Multi-party Computation.- Cryptosystems II.- A Simple BGN-Type Cryptosystem from LWE.- Bonsai Trees, or How to Delegate a Lattice Basis.- Efficient Lattice (H)IBE in the Standard Model.- Hash and MAC.- Multi-property-preserving Domain Extension Using Polynomial-Based Modes of Operation.- Stam's Collision Resistance Conjecture.- Universal One-Way Hash Functions via Inaccessible Entropy.- Foundational Primitives.- Constant-Round Non-malleable Commitments from Sub-exponential One-Way Functions.- Constructing Verifiable Random Functions with Large Input Spaces.- Adaptive Trapdoor Functions and Chosen-Ciphertext Security.

Advances in cryptology -- EUROCRYPT 2010 : 29th Annual International Conference on the Theory and Applications of Cryptographic Techniques, French Riviera, May 30-June 3, 2010 : proceedings

The U.S. National Security Agency (NSA) developed the Simon and Speck families of lightweight block ciphers as an aid for securing applications in very constrained environments where AES may not be suitable. This paper summarizes the algorithms, their design rationale, along with current cryptanalysis and implementation results.

/pdf/simon-and-speck-block-ciphers-for-the-internet-of-things-2vkz23sw1g.pdf

SIMON and SPECK: Block Ciphers for the Internet of Things.

In this paper, we propose a new lightweight block cipher named RECTANGLE. The main idea of the design of RECTANGLE is to allow lightweight and fast implementations using bit-slice techniques. RECTANGLE uses an SP-network. The substitution layer consists of 16 4 4 S-boxes in parallel. The permutation layer is composed of 3 rotations. As shown in this paper, RECTAN- GLE offers great performance in both hardware and software environment, which provides enough flexibility for different application scenario. The following are 3 main advantages of RECTANGLE. First, RECTANGLE is extremely hardware-friendly. For the 80-bit key version, a one-cycle-per-round parallel implementation only needs 1600 gates for a throughput of 246 Kbits/sec at 100 KHz clock and an energy efficiency of 3.0 pJ/bit. Second, RECTANGLE achieves a very competitive software speed among the existing lightweight block ciphers due to its bit-slice style. Using 128-bit SSE instruc- tions, a bit-slice implementation of RECTANGLE reaches an average encryption speed of about 3.9 cycles/byte for messages around 3000 bytes. Last, but not least, we propose new design criteria for the RECTANGLE S-box. Due to our careful selection of the S-box and the asymmetric design of the permutation layer, RECTANGLE achieves a very good security-performance tradeoff. Our extensive and deep security analysis shows that the highest number of rounds that we can attack, is 18 (out of 25).

/pdf/rectangle-a-bit-slice-lightweight-block-cipher-suitable-for-4w2dvsdvma.pdf

RECTANGLE: a bit-slice lightweight block cipher suitable for multiple platforms

This paper presents a 64-bit lightweight block cipher TWINE supporting 80 and 128- bit keys. TWINE realizes quite small hardware implementation similar to the previous lightweight block cipher proposals, yet enables efficient software implementations on various platforms, from micro-controller to high-end CPU. This characteristic is obtained by the use of generalized Feistel structure combined with an improved block shuffle, introduced at FSE 2010. Keywords: lightweight block cipher, generalized Feistel structure, block shuffle

TWINE: A Lightweight Block Cipher for Multiple Platforms ⋆

This paper presents a 64-bit lightweight block cipher \(\textnormal{\textsc{TWINE}}\) supporting 80 and 128-bit keys. \(\textnormal{\textsc{TWINE}}\) realizes quite small hardware implementation similar to the previous lightweight block cipher proposals, yet enables efficient software implementations on various CPUs, from micro-controllers to high-end CPUs. This characteristic is obtained by the use of generalized Feistel combined with an improved block shuffle, introduced at FSE 2010.

/pdf/textnormal-textsc-twine-a-lightweight-block-cipher-for-1abxaetrl0.pdf

\textnormal{\textsc{TWINE}}: A Lightweight Block Cipher for Multiple Platforms

We implemented node monitoring subsystem on a small FPGA using low delay architecture and overdetermined linear system to reduce the computational complexity. Processing time of monitored data was below 250ns except for required filtering time.

Eita Kobayashi

Papers

TWINE: A Lightweight Block Cipher for Multiple Platforms ⋆

\textnormal{\textsc{TWINE}}: A Lightweight Block Cipher for Multiple Platforms

Fast and Compact Node Monitoring System for Multi-Vendor Optical Network