Delegate predicate encryption and its application to anonymous authentication

Abstract

Predicate encryption provides fine-grained control over encryption and decryption. In a predicate encryption scheme, message is encrypted with a set of attributes, and decryption key is incorporated with a predicate. Only when the predicate evaluates to true over these attributes, the message can be correctly decrypted. We propose an extension to predicate encryption named delegate predicate encryption. In our extension, a user generates a encryption capability of a set of attributes, then sends the capability to a encryption proxy. Using this capability, the proxy can encrypt arbitrary message with these attributes without knowing anything about these attributes. We give a concrete construction from a predicate encryption scheme which supports the widest range of predicate known to date. Then, using our extension, we are able to construct an anonymous authentication scheme. In our anonymous authentication scheme, authentication rules can be described in an very expressive way, while the anonymity of user is protected and the authentication rules are also hidden.

Homomorphic Encryption with Access Policies: Characterization and New Constructions

“…Generalizing from the results of [32], this corollary follows from the property of attribute-hiding Corollary 1. An attribute-hiding HPE scheme is a DPE as defined in [32] if there exists a γ ∈ Γ such that (A × M, γ) is unital.…”

“…The user can distribute this to certain parties who can then encrypt messages with attribute a obliviously. The realization in [32] is similar to the widely-used technique of publishing encryptions of "zero" in a homomorphic cryptosystem, which can then be treated as a key. In fact, this technique is adopted in [33] to transform a strongly homomorphic private-key scheme into a public-key one.…”

“…Delegate Predicate Encryption A primitive presented in [32] called "Delegate Predicate Encryption" (DPE) ‡ enables a user to generate an encryption key associated with a chosen attribute a ∈ A, which does not reveal anything about a. The user can distribute this to certain parties who can then encrypt messages with attribute a obliviously.…”

Functional Credentials

“…The problem of delegated verification has been first proposed, but not thoroughly formalized, in the work of Wei and Ye [44]. Their solution leverages the homomorphic properties of the predicate encryption scheme of Katz et al [34], but only achieves semi-honest security.…”

A Survey of the Security and Privacy Measures for Anonymous Biometric Authentication Systems

“…al [5] classify adversarial behaviors broadly in two classes: semi-honest and malicious. A semi-honest adversary follows the protocol faithfully but attempts to find out additional information about the other parties involved in the protocol.…”