40-bit encryption

About: 40-bit encryption is a research topic. Over the lifetime, 5434 publications have been published within this topic receiving 149016 citations.

SEA: a scalable encryption algorithm for small embedded applications

Abstract: Most present symmetric encryption algorithms result from a tradeoff between implementation cost and resulting performances In addition, they generally aim to be implemented efficiently on a large variety of platforms In this paper, we take an opposite approach and consider a context where we have very limited processing resources and throughput requirements For this purpose, we propose low-cost encryption routines (ie with small code size and memory) targeted for processors with a limited instruction set (ie AND, OR, XOR gates, word rotation and modular addition) The proposed design is parametric in the text, key and processor size, allows efficient combination of encryption/decryption, “on-the-fly” key derivation and its security against a number of recent cryptanalytic techniques is discussed Target applications for such routines include any context requiring low-cost encryption and/or authentication

On Notions of Security for Deterministic Encryption, and Efficient Constructions without Random Oracles

Abstract: The study of deterministic public-key encryption was initiated by Bellare et al. (CRYPTO '07), who provided the "strongest possible" notion of security for this primitive (called PRIV) and constructions in the random oracle (RO) model. We focus on constructing efficient deterministic encryption schemes withoutrandom oracles. To do so, we propose a slightly weaker notion of security, saying that no partial information about encrypted messages should be leaked as long as each message is a-priori hard-to-guess given the others(while PRIV did not have the latter restriction). Nevertheless, we argue that this version seems adequate for many practical applications. We show equivalence of this definition to single-message and indistinguishability-based ones, which are easier to work with. Then we give general constructions of both chosen-plaintext (CPA) and chosen-ciphertext-attack (CCA) secure deterministic encryption schemes, as well as efficient instantiations of them under standard number-theoretic assumptions. Our constructions build on the recently-introduced framework of Peikert and Waters (STOC '08) for constructing CCA-secure probabilisticencryption schemes, extending it to the deterministic-encryption setting as well.

Image encryption using the two-dimensional logistic chaotic map

Abstract: Chaos maps and chaotic systems have been proved to be useful and effective for cryptography. In our study, the two-dimensional logistic map with complicated basin structures and attractors are first used for image encryption. The proposed method adopts the classic framework of the permutation-substitution network in cryptography and thus ensures both confusion and diffusion properties for a secure cipher. The proposed method is able to encrypt an intelligible image into a random-like one from the statistical point of view and the human visual system point of view. Extensive simulation results using test images from the USC-SIPI image database demonstrate the effectiveness and robustness of the proposed method. Security analysis results of using both the conventional and the most recent tests show that the encryption quality of the proposed method reaches or excels the current state-of-the-art methods. Similar encryption ideas can be applied to digital data in other formats (e.g., digital audio and video). We also publish the cipher MATLAB open-source-code under the web page https://sites.google.com/site/tuftsyuewu/source-code.

Revocation Systems with Very Small Private Keys

Abstract: In this work, we design a method for creating public key broadcast encryption systems. Our main technical innovation is based on a new "two equation" technique for revoking users. This technique results in two key contributions: First, our new scheme has ciphertext size overhead $O(r)$, where $r$ is the number of revoked users, and the size of public and private keys is only a \emph{constant} number of group elements from an elliptic-curve group of prime order. In addition, the public key allows us to encrypt to an unbounded number of users. Our system is the first to achieve such parameters. We give two versions of our scheme: a simpler version which we prove to be selectively secure in the standard model under a new, but non-interactive assumption, and another version that employs the new dual system encryption technique of Waters to obtain adaptive security under the d-BDH and decisional Linear assumptions. Second, we show that our techniques can be used to realize Attribute-Based Encryption (ABE) systems with non-monotonic access formulas, where our key storage is significantly more efficient than previous solutions. This result is also proven selectively secure in the standard model under our new non-interactive assumption.

Secure Integration of Asymmetric and Symmetric Encryption Schemes

Abstract: This paper presents a generic conversion from weak asymmetric and symmetric encryption schemes to an asymmetric encryption scheme that is chosen-ciphertext secure in the random oracle model. Our conversion is the first generic transformation from an arbitrary one-way asymmetric encryption scheme to a chosen-ciphertext secure asymmetric encryption scheme in the random oracle model.