Attribute Based Broadcast Encryption with Short Ciphertext and Decryption Key
Attribute Based Broadcast Encryption (ABBE) is a combination of Attribute Based Encryption (ABE) and Broadcast Encryption (BE). It allows a broadcaster (or encrypter) to broadcast an encrypted message that can only be decrypted by the receivers who are wi
- PDF / 324,557 Bytes
- 18 Pages / 439.37 x 666.142 pts Page_size
- 110 Downloads / 222 Views
Centre for Computer and Information Security Research, School of Computing and Information Technology, University of Wollongong, Wollongong, Australia [email protected], {gyang,wsusilo}@uow.edu.au 2 State Key Laboratory of Integrated Service Networks, Xidian University, Xi’an, People’s Republic of China [email protected]
Abstract. Attribute Based Broadcast Encryption (ABBE) is a combination of Attribute Based Encryption (ABE) and Broadcast Encryption (BE). It allows a broadcaster (or encrypter) to broadcast an encrypted message that can only be decrypted by the receivers who are within a predefined user set and satisfy the access policy specified by the broadcaster. Compared with normal ABE, ABBE allows direct revocation, which is important in many real-time broadcasting applications such as Pay TV. In this paper, we propose two novel ABBE schemes that have distinguishing features: the first scheme is key-policy based and has short ciphertext and constant size decryption key; and the second one is ciphertext-policy based and has constant size ciphertext and short decryption key. Both of our schemes allow access policies to be expressed using AND-gate with positive, negative, and wildcard symbols, and are proven secure under the Decision n-BDHE assumption without random oracles. Keywords: Attribute based encryption · Broadcast encryption · ANDgate · Wildcard
1
Introduction
Broadcast encryption (BE), introduced by Berkovits [1] and Fiat and Naor [2], is a very useful tool for securing a broadcast channel. In a traditional BE scheme, a broadcaster can specify a subset of privileged users (out of the user universe) as the legitimate receivers of a message. Due to the practicality of broadcast encryption in real-world applications, many BE schemes have been proposed in various settings since its introduction (e.g., [3–9]). Attribute Based Encryption (ABE), first introduced by Sahai and Waters [10], allows an encrypter to embed a fine-grained access policy into the ciphertext when encrypting a message. There are two types of ABE. In a Ciphertext Policy (CP) ABE system, each user secret key is associated with a set of user attributes, and every ciphertext is associated with an access policy. A ciphertext can be c Springer International Publishing Switzerland 2015 G. Pernul et al. (Eds.): ESORICS 2015, Part II, LNCS 9327, pp. 252–269, 2015. DOI: 10.1007/978-3-319-24177-7 13
A.B.Broadcast Encryption with Short Ciphertext and Decryption Key
253
decrypted by a secret key if and only if the attributes associated with the secret key satisfy the access policy in the ciphertext. Key Policy (KP) ABE is the dual form of CP-ABE, where attributes are used in the encryption process, and access policies are used in the user secret key generation. ABE systems can provide fine-grained access control of encrypted data, and has been extensively studied in recent years (e.g., [11–16]). Since ABE gives a one-to-many relationship between a ciphertext and the corresponding valid decryption keys, it can be considered as a natural br
Data Loading...
