Certificate-based Encryption Scheme Research Articles

Enhanced Certificate-Based Encryption from pairings

In Certificate-Based Encryption, introduced by Gentry, a certificate, -or, more generally, a signature-acts not only as a certificate but also as a decryption key. However, the security model of Gentry’s scheme relies on an unrealistic assumption, where the adversary must reveal its partial private key to the challenger in attack games. In this paper, we propose an enhanced Certificate-Based Encryption scheme from pairings in the chosen-key model. We show that this scheme is semantically secure against adaptive chosen ciphertext attacks in the random oracle model under the Bilinear Diffie–Hellman (BDH) assumption. The new scheme not only solves the key escrow problem and the secure channel problem to be inherent in Identity-Based Encryption schemes, but also eliminates the unrealistic assumption of Gentry scheme. Moreover, the proposed scheme is more efficient and secure than the existing related works.

Forward-Secure Certificate-Based Encryption and its Generic Construction

In this paper, we introduce a new asymmetric encryption paradigm called Forward-Secure Certificate-Based Encryption. It preserves the advantages of certificate-based encryption (CBE) such as implicit certificate and no private key escrow. At the same time it also inherits the properties of the forward-secure public key encryption. In a forward-secure CBE scheme, all users’ private keys are updated at regular periods throughout the lifetime of the system; exposure of a user’s private key corresponding to a given time period does not enable an adversary to break the security of the ciphertext sent to this user for any prior time period. We first provide the formal definition for forward-secure CBE and its security model. Then we propose a generic construction of forward-secure CBE and prove it to be secure against chosen plaintext attacks in the standard model. We also describe how this construction can be enhanced to achieve security against adaptive chosen-ciphertext attacks both in the standard model and in the random oracle model. Finally, a concrete forward-secure CBE scheme is constructed.

Constructing Efficient Certificate-based Encryption with Paring

The certificate-based encryption (CBE) is a new PKC paradigm which combines traditional public-key encryption (PKE) and identity based encryption (IBE) while preserving their features. CBE provides an efficient implicit certificate mechanism to eliminate third-party queries for the certificate status and to simply the certificate revocation problem. Therefore, CBE can be used to construct an efficient PKI requiring fewer infrastructures. In addition, it also solves the key escrow problem and key distribution problem inherent in IBE. In this paper, we construct an efficient CBE scheme with paring and prove it to be CCAsecure in the random oracle model based on the hardness of the Bilinear Diffie-Hellman Inversion assumption. When compared with other existing CBE schemes, our scheme has obvious advantage in the computation performance.

Improved certificate-based encryption in the standard model

Certificate-based encryption has been recently proposed as a means to simplify the certificate management inherent to traditional public key encryption. In this paper, we present an efficient certificate-based encryption scheme which is fully secure in the standard model. Our construction is more efficient (in terms of computational cost and ciphertext size) than any of the previous constructions known without random oracles.

On the Security of Status Certificate-Based Encryption Scheme

In this paper, we will show that the status certificate-based encryption scheme proposed by Yum and Lee is insecure against key substitution attacks by two types of attackers.