METHOD AND SYSTEM FOR DATA SHARING USING ATTRIBUTE-BASED ENCRYPTION IN CLOUD COMPUTING

摘要

The present invention relates to a method for sharing data using an attribute-based encryption in a cloud computing environment and a system thereof, which always guarantee a cryptogram of a constant size. The method of the present invention comprises: a setup step of generating a master key (MK) and a public key (PK); a key generation step of generating a secret key (SK_u) and transmitting the same to a corresponding user terminal; a step of storing a unique value (c) and an ID (id_u) of a user (u) in an entire user ID table (T); an encryption step of transmitting a cryptogram (CT) to a cloud server; a cryptogram request step; and a decoding step.