Systems and methods for data encryption and decryption in data transmission

A fine-grained mobile access encryption system, comprising:

• at least one storage medium storing a set of instructions;
• and
• at least one hardware processor configured to communicate with the at least one storage medium, wherein when executing the set of instructions, the at least one hardware processor is directed to:
• generate one or more public key parameters pp and a master key msk based on a system security parameter λ, wherein to generate the one or more public key parameters pp and the master key msk based on the system security parameter λ, the at least one hardware processor is directed to:
• determine a prime p and bilinear groups by a private key generator (PKG) based on the system security parameter λ;
• determine a revocation identity domain u and a validation domain v;
• select a Hash function UCH and an auxiliary parameter domain R through the PKG;
• select random numbers g and h and random exponents α and b from the bilinear groups through the PKG;
• and
• generate the one or more public key parameters pp and the master key msk, wherein
• u
• =
• [
• 0
• ,
• p
• -
• 1
• 2
• ]
• ,
• v
• =
• [
• p
• +
• 1
• 2
• ,
• p
• -
• 1
• ]
• ,
• α
• ⁢
• ⁢
• b
• ∈
• Z
• p
• ,
• pp=(g, gb, gb2, hb, e(g,g)α, UCH, R) e denotes a mapping function for determining bilinear groups, and msk=(α, b);
• obtain an identity attribute of a user;
• and
• generate a private key skI of the user based on the identity attribute and the master key;
• encrypt offline data to generate a session key key1 of the offline data and a proxy cipher text ict of the offline data;
• and
• encrypt online data to generate a session key key2 of the online data and a proxy cipher text ct of the online data.