Anonymous Hierarchical Identity-based Encryption Scheme Research Articles

Anonymous hierarchical identity-based encryption with bounded leakage resilience and its application

Hierarchical identity-based encryption can be used to protect the sensitive data in cloud system. However, as the traditional security model does not capture side-channel attacks, many hierarchical identity-based encryption schemes do not resist this kind of attack, which can exploit various forms of unintended information leakage. Inspired by these, leakage-resilience cryptography formalises some models of side-channel attacks. In this paper, we consider the memory leakage resilience in anonymous hierarchical identity-based encryption schemes. By applying Lewko et al.'s tools, we construct a master key leakage-resilient anonymous hierarchical identity-based encryption scheme based on dual system encryption techniques. As an interesting application of our scheme, we consider security for public-key encryption with multi-keyword ranked search (PEMKRS) in the presence of secret key leakage in the trapdoor generation algorithm, and provide a generic construction of leakage-resilient secure PEMKRS from a master key leakage-resilient anonymous hierarchical identity-based encryption scheme.

Anonymous hierarchical identity-based encryption with bounded leakage resilience and its application

Hierarchical identity-based encryption can be used to protect the sensitive data in cloud system. However, as the traditional security model does not capture side-channel attacks, many hierarchical identity-based encryption schemes do not resist this kind of attack, which can exploit various forms of unintended information leakage. Inspired by these, leakage-resilience cryptography formalises some models of side-channel attacks. In this paper, we consider the memory leakage resilience in anonymous hierarchical identity-based encryption schemes. By applying Lewko et al.'s tools, we construct a master key leakage-resilient anonymous hierarchical identity-based encryption scheme based on dual system encryption techniques. As an interesting application of our scheme, we consider security for public-key encryption with multi-keyword ranked search (PEMKRS) in the presence of secret key leakage in the trapdoor generation algorithm, and provide a generic construction of leakage-resilient secure PEMKRS from a master key leakage-resilient anonymous hierarchical identity-based encryption scheme.

Compact Anonymous Hierarchical Identity-Based Encryption with Constant Size Private Keys: TABLE 1.

We present a new construction of anonymous hierarchical identity-based encryption (HIBE) over prime order groups. The distinct feature of our proposed scheme is that both private key and ciphertext have a constant size, which has never been achieved in all other existing anonymous HIBE schemes. Moreover, we utilized a double exponent technique to generate the ciphertext in order to provide anonymity. This simple and efficient method allows us to construct a more compact anonymous HIBE in prime order groups. Under the decisional bilinear |$n+1$|-Diffie–Hellman exponent assumption and linear assumption, we show that the proposed scheme is secure and anonymous against chosen plaintext attacks in the standard model.

Multi-keyword ranked searchable public-key encryption

Most related works on Public-Key Encryption with Keyword Search scheme also called Searchable Public-key Encryption focus on single keyword search. Some works supporting multi-keyword search cannot provide search result ranking. In this paper, we study the problem of multi-keyword ranked search over encrypted data in public-key model. We propose the definition of Multi-Keyword Ranked Searchable Public-key Encryption/Public-Key Encryption with Multi-Keyword Ranked Search. In the definition, we allow the receiver to query any set of keywords. As the query result, the receiver can get the number of queried keywords appearing in the encrypted data, which can be used to evaluate the similarity ranking of the data keywords to the search query in 'as many matches as possible' principle. We put forward a generic construction for public-key encryption with multi-keyword ranked search scheme with sub-linear ciphertext based on any anonymous hierarchical identity-based encryption scheme and provide the security analysis. At last, we present a concrete scheme with sub-linear ciphertext.

Anonymous HIBE with short ciphertexts: full security in prime order groups

Anonymous Hierarchical Identity-Based Encryption (HIBE) is an extension of Identity-Based Encryption (IBE), and it provides not only a message hiding property but also an identity hiding property. Anonymous HIBE schemes can be applicable to anonymous communication systems and public key encryption systems with keyword searching. However, previous anonymous HIBE schemes have some disadvantages that the security was proven in the weaker model, the size of ciphertexts is not short, or the construction was based on composite order bilinear groups. In this paper, we propose the first efficient anonymous HIBE scheme with short ciphertexts in prime order (asymmetric) bilinear groups, and prove its security in the full model with an efficient reduction. To achieve this, we use the dual system encryption methodology of Waters. We also present the benchmark results of our scheme by measuring the performance of our implementation.

Anonymous HIBE: Compact Construction Over Prime-Order Groups

We present an anonymous hierarchical identity based encryption (HIBE) scheme that not only achieves constant-size ciphertext, but also works in bilinear groups with prime order. In contrast to our work, all previous anonymous HIBE schemes either have ciphertext size linear in the depth of the hierarchy or work in bilinear groups with a composite order. Our construction is more efficient than previous schemes in terms of ciphertext size and decryption cost. We give provable security of our construction, consisting of confidentiality and anonymity, without random oracles. To gain anonymity, we introduce a novel and simple method called “double exponent” technique, which gives an anonymous HIBE scheme more compact than the result at CRYPTO 2006. Our method is quite general in that it works on both symmetric and asymmetric bilinear maps. The simple method might also be of independent interest to gain anonymity of attributes in constructing searchable encryption schemes on encrypted data.

New Techniques for Anonymous HIBE with Short Ciphertexts in Prime Order Groups

Anonymous hierarchical identity based encryption (HIBE) is an extension of identity based encryption (IBE) that can use an arbitrary string like an e-mail address for a public key, and it additionally provide the anonymity of identity in ciphertexts. Using the anonymous HIBE schemes, it is possible to construct anonymous communication systems and public key encryption with keyword search. This paper presents an anonymous HIBE scheme with constant size ciphertexts under prime order symmetric bilinear groups, and shows that it is secure under the selective security model. Previous anonymous HIBE schemes were constructed to have linear size ciphertexts, to use composite order bilinear groups, or to use asymmetric bilinear groups that is a special type of bilinear groups. Our construction is the first efficient anonymous HIBE scheme that has constant size ciphertexts and that uses prime order symmetric bilinear groups. Compared to the previous scheme of composite order bilinear groups, ours is ten times faster. To achieve our construction, we first devise a novel cancelable random blinding technique. The random blinding property of our technique provides the anonymity of our construction, and the cancellation property of our technique enables decryption.