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.

Dual encryption protocol for scalable secure group communication

Abstract: A logical tree structure (10) and method for managing membership in a multicast group provides scalability and security from internal attacks. The structure defines key groups (20) and subgroups (24, 22), with each subgroup having a subgroup manager (12, 14, 18). Dual encryption allows the sender (12) of the multicast data to manage distribution of a first set of encryption keys whereas the individual subgroup managers (12, 14, 18) manage the distribution of a second set of encryption keys. The two key sets allow the sender (12) to delegate much of the group management responsibilities without compromising security because a key from each set is required to access the multicast data. Security is further maintained via a method in which subgroup managers (12, 14, 18) can be either members (18) or participants (14). Access to both keys is provided to members (18) whereas access to only one key is provided to participants (14). Nodes can be added without generating a new encryption key at the top level which provides improved scalability.

Biometric Based Cryptographic Key Generation from Faces

Abstract: Existing asymmetric encryption algorithms require the storage of the secret private key. Stored keys are often protected by poorly selected user passwords that can either be guessed or obtained through brute force attacks. This is a weak link in the overall encryption system and can potentially compromise the integrity of sensitive data. Combining biometrics with cryptography is seen as a possible solution but any biometric cryptosystem must be able to overcome small variations present between different acquisitions of the same biometric in order to produce consistent keys. This paper discusses a new method which uses an entropy based feature extraction process coupled with Reed-Solomon error correcting codes that can generate deterministic bit-sequences from the output of an iterative one-way transform. The technique is evaluated using 3D face data and is shown to reliably produce keys of suitable length for 128-bit Advanced Encryption Standard (AES).

Revisiting Attribute-Based Encryption With Verifiable Outsourced Decryption

Abstract: Attribute-based encryption (ABE) is a promising technique for fine-grained access control of encrypted data in a cloud storage, however, decryption involved in the ABEs is usually too expensive for resource-constrained front-end users, which greatly hinders its practical popularity. In order to reduce the decryption overhead for a user to recover the plaintext, Green et al. suggested to outsource the majority of the decryption work without revealing actually data or private keys. To ensure the third-party service honestly computes the outsourced work, Lai et al. provided a requirement of verifiability to the decryption of ABE, but their scheme doubled the size of the underlying ABE ciphertext and the computation costs. Roughly speaking, their main idea is to use a parallel encryption technique, while one of the encryption components is used for the verification purpose. Hence, the bandwidth and the computation cost are doubled. In this paper, we investigate the same problem. In particular, we propose a more efficient and generic construction of ABE with verifiable outsourced decryption based on an attribute-based key encapsulation mechanism, a symmetric-key encryption scheme and a commitment scheme. Then, we prove the security and the verification soundness of our constructed ABE scheme in the standard model. Finally, we instantiate our scheme with concrete building blocks. Compared with Lai et al. ’s scheme, our scheme reduces the bandwidth and the computation costs almost by half.

Comparison of data encryption algorithms

Abstract: This paper tries to present a fair comparison between the most common and used algorithms in the data encryption field. The two main characteristics that identify and differentiate one encryption algorithm from another are its ability to secure the protected data against attacks and its speed and efficiency in doing so. This paper provides a performance comparison between four of the most common encryption algorithms: DES, 3DES, Blowfish and AES. The comparison has been conducted by running several encryption settings to process different sizes of data blocks

Hidden ciphertext policy attribute-based encryption under standard assumptions

Abstract: We propose two new ciphertext policy attribute-based encryption (CP-ABE) schemes where the access policy is defined by AND-gate with wildcard. In the first scheme, we present a new technique that uses only one group element to represent an attribute, while the existing ABE schemes of the same type need to use three different group elements to represent an attribute for the three possible values (namely, positive, negative, and wildcard). Our new technique leads to a new CP-ABE scheme with constant ciphertext size, which, however, cannot hide the access policy used for encryption. The main contribution of this paper is to propose a new CP-ABE scheme with the property of hidden access policy by extending the technique we used in the construction of our first scheme. In particular, we show a way to bridge ABE based on AND-gate with wildcard with inner product encryption and then use the latter to achieve the goal of hidden access policy. We prove that our second scheme is secure under the standard decisional linear and decisional bilinear Diffie-Hellman assumptions.