  Attribute-Based Encryption (ABE) has emerged as an information-centric
public-key cryptographic system which allows a data owner to share data,
according to access policy, with multiple data users based on the attributes
they possess, without knowing their identities. In the original ABE schemes, a
central authority administrates the system and issues secret keys to data users
based on their attributes and both the owner and users need to trust a specific
CA. However, in certain real-world applications, the data users would not trust
anyone but themselves. For such situations, we introduce a new decentralization
model of ABE, termed Data User-based ABE (DU-ABE), which is managed jointly by
the data users. DU-ABE is the first decentralized ABE scheme that replaces the
authorities with the data users without employing any other extra entities.
