Direct Chosen-Ciphertext Secure Identity-Based Encryption in the Standard Model with short Ciphertexts

Chosen-Ciphertext Secure Identity-Based Encryption in the Standard Model with short Ciphertexts

We describe a practical identity-based encryption scheme that is secure in the standard model against chosen-ciphertext (CCA2) attacks. Security is based on an assumption comparable to (but slightly stronger than) Bilinear Decisonal Diffie-Hellman (BDDH). A comparison shows that our construction outperforms all known identity-based encryption schemes in the standard model and its performance is...

Direct Chosen-Ciphertext Secure Identity-Based Key Encapsulation Without Random Oracles

We describe a new and practical identity-based key encapsulation mechanism that is secure in the standard model against chosen-ciphertext (CCA2) attacks. Since our construction is direct and not based on hierarchical identity-based encryption, it is more efficient than all previously proposed schemes. Furthermore, we give the first chosen-ciphertext secure identity-based key encapsulation mecha...

Chosen-ciphertext secure multi-hop identity-based conditional proxy re-encryption with constant-size ciphertexts

Conditional Proxy Broadcast Re-Encryption

A proxy re-encryption (PRE) scheme supports the delegation of decryption rights via a proxy, who makes the ciphertexts decryptable by the delegatee. PRE is useful in various applications such as encrypted email forwarding. In this paper, we introduce a more generalized notion of conditional proxy broadcast re-encryption (CPBRE). A CPBRE scheme allows Alice to generate a re-encryption key for so...

Achieving Short Ciphertexts or Short Secret-Keys for Adaptively Secure General Inner-Product Encryption

In this paper, we present two non-zero inner-product encryption (NIPE) schemes that are adaptively secure under a standard assumption, the decisional linear (DLIN) assumption, in the standard model. One of the proposed NIPE schemes features constant-size ciphertexts and the other features constant-size secret-keys. Our NIPE schemes imply an identity-based revocation (IBR) system with constant-s...