In this work, we design a new attribute-based encryption scheme with the revocation capability. In the proposed schemes, the user (broadcaster) encrypts the data according to an access policy over the set of attributes, and a list of the identities of revoked users. Only recipients who have attributes which satisfy the access policy and whose identity is not in the list of revoked users will be...

A broadcast encryption scheme allows the sender to securely distribute data to a dynamically changing set of users over an insecure channel. One of the most challenging settings for this problem is that of stateless receivers, where each user is given a fixed set of keys which cannot be updated through the lifetime of the system. This setting was considered by Naor, Naor and Lotspiech [17], who...

We consider broadcast encryption schemes wherein a center needs to broadcast a secret message to a privileged set of receivers. We prescribe a probability distribution P on the privileged set. In this setting, the transmission overhead can be viewed as a random variable over P and we define its expected value as the average transmission overhead (or ato). Given P, the Shannon’s entropy function...

In this paper we extend the notion of hierarchical identitybased encryption with wildcards (WIBE) from the domain of a single Trusted Authority (TA) to a setting with multiple, independent Trusted Authorities each with their own WIBE. In this multi-trust-authority WIBE environment, a group of TA’s may form coalitions, enabling secure communication across domains. These coalitions can be created...

Motivated by the lattice basis delegation technique due to [8], we propose an adaptively secure identity-based broadcast encryption(IBBE) scheme based on the hard worst-case lattice problems. Our construction can be generalized to a hierarchical IBBE (HIBBE) easily. Using the method in [1], we also modify our basic construction to obtain an IBBE in the standard model. To the best of the authors...

The most influential broadcast encryption (BE) scheme till date was introduced in 2001 by Naor, Naor and Lotspiech (NNL) and is based on binary trees. This paper generalizes the ideas of NNL to obtain BE schemes based on k-ary trees for any k ≥ 2. The treatment is uniform across all k and essentially provides a single scheme which is parameterized by the arity of the underlying tree. We perform...

Many users store their data in a cloud, which might not be fully trusted, for the purpose of convenient data access and sharing. For efficiently accessing the stored data, keyword search can be performed by the cloud server remotely with a single query from the user. However, the cloud server cannot directly search the data if it is encrypted. One of solutions could be to allow the user to down...

In broadcast networks, it is often required to encrypt data so that only a privileged set of users with access to the session key can access the data. The standard technique of transferring the session key to each user individually does not scale with the number of users typically found on a network such as cable. This method is not only time-wise inefficient, but also incurs high communication...

In this paper, we present an efficient public-key broadcast encryption (PKBE) scheme with sublinear size of public keys, private keys, and ciphertexts and prove its adaptive security under standard assumptions. Compared with the currently best scheme that provides adaptive security under standard assumptions and sub-linear size of various parameters, the ciphertext size of our scheme is 94% sho...

We propose a new broadcast encryption scheme based on polynomial interpolations. Our scheme, obtained from the Naor-Pinkas scheme by partitioning the user set and interpolating multiple polynomials, turns out to be better in efficiency than the best known broadcast schemes like the Subset Difference and the Layered Subset Difference methods, which are tree based schemes. More precisely, when r ...