Systems and methods for data encryption and decryption in data transmission

1. A method for a fine-grained mobile access encryption, comprising:

generating one or more public key parameters pp and a master key msk based on a system security parameter λ, wherein the generating the one or more public key parameters pp and the master key msk based on the system security parameter λ comprises:

determining a prime p and bilinear groups by a private key generator (PKG) based on the system security parameter λ;

determining a revocation identity domain u and a validation domain v;

selecting a Hash function UCH and an auxiliary parameter domain R through the PKG;

selecting random numbers g and h and random exponents α and b from the bilinear groups through the PKG; and

generating the one or more public key parameters pp and the master key msk, wherein

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v

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pp=(g, g b , g b 2 , h b , e(g,g) α , UCH, R), e denotes a mapping function for determining bilinear groups, and msk=(α, b);

obtaining an identity attribute of a user;

generating a private key sk I of the user based on the identity attribute and the master key msk;

encrypting offline data to generate a session key key1 of the offline data and a proxy cipher text ict of the offline data; and

encrypting online data to generate a session key key2 of the online data and a proxy cipher text ct of the online data.

2. The method of claim 1 , wherein the determining the prime p and the bilinear groups by the PKG based on the system security parameter λ comprises:

determining the prime p by the PKG based on the system security parameter λ;

determining a first group G and a second group G T based on the system security parameter λ; and

mapping one or more elements in the first group G to the second group G T using a mapping function to determine the bilinear groups.

3. The method of claim 1 , wherein the generating the private key sk I of the user based on the identity attribute and the master key msk comprises:

selecting a random exponent t through the PKG;

obtaining the identity attribute of the user; and

generating the private key sk I of the user based on the random exponent t, the identity attribute, and the master key msk,

wherein sk I =(d 0 , d 1 , d 2 )=(g α , g b 2 t , (g b·I h) t , g −t ), d 0 , d 1 , and d 2 are components of the private key sk I , t∈Z p , I denotes the identity attribute of the user.

4. The method of claim 3 , wherein the encrypting the offline data to generate the session key key1 of the offline data and the proxy cipher text ict of the offline data comprises:

randomly selecting a first revocation set S ori ={I ori,l , . . . , I ori,n };

obtaining a Hash function pair (chk, td), wherein chk and td are two parameters of the Hash function pair;

selecting a random number r′;

determining a dynamic authentication I v ;

selecting a random number s and random exponents s i and s v ;

determining cipher texts C 0 =g s , C i,1 =g bs i , C i,2 =(g b 2 I i h b ) s i , C v,1 =g bs v , and C v,2 =(g b 2 I v h b ) s v ; and

determining the session key key1 of the offline data and the proxy cipher text ict of the offline data,

wherein, n denotes a count of revoked users, I i ∈u, i∈[n], n=|S ori |, I v =UCHash(chk, I ori,1 ∥ . . . ∥I ori,n , r′), UCHash denotes a chameleon hash function, s∈Z p , s i ∈Z p , s v ∈Z p , key1=e(g,g) αs , and ict=(key1, C 0 , (C i,1 , C i,2 ) i∈[n] , C v,1 , C v,2 , S ori , I v , (s i ) i∈[n] , s v , s, chk, td, r′).

5. The method of claim 4 , wherein the encrypting online data to generate the session key key2 of the online data and the proxy cipher text ct of the online data comprises:

obtaining a second revocation set S={I 1 , . . . , I |S| };

determining I mall,i =(I i −I ori,i )·s i ;

determining a cipher text r; and

determining the session key key2 of the online data and the proxy cipher text ct of the online data, wherein i∈[|S|], r=UColl(td, I ori,1 ∥ . . . ∥I ori,|S| , r′, X), UColl denotes a collision hash function, X=C 0 ∥{C i,1 ∥C i,2 } i∈[|S|] ∥C v,1 ∥C v,2 ∥{I mall,i } i∈[|S|] , key2=e(g,g) αs , and ct=(C 0 , (C i,1 , C i,2 ) i∈[|S|] , C v,1 , C v,2 , {I mall,i } i∈[|S|] , chk, r).

6. 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, g b , g b 2 , h b , 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 sk I 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.

7. The system of claim 6 , wherein the at least one hardware processor is further directed to:

determine the prime p by the PKG based on the system security parameter λ;

determine a first group G and a second group G T based on the system security parameter λ; and

map one or more elements in the first group G to the second group G T using a mapping function e to determine the bilinear groups.

8. The system of claim 6 , wherein the at least one hardware processor is further directed to:

select a random exponent t through the PKG;

obtain the identity attribute of the user; and

generate the private key sk I of the user based on the random exponent t, the identity attribute, and the master key msk,

wherein sk I =(d 0 , d 1 , d 2 )=(g α , g b 2 t , (g b·I h) t , g −t ), d 0 , d 1 , and d 2 are components of the private key sk I , t∈Z p , I denotes the identity attribute of the user.

9. The system of claim 8 , wherein the at least one hardware processor is further directed to:

randomly select a first revocation set S ori ={I ori,1 , . . . , I ori,n };

obtain a Hash function pair (chk, td), wherein chk and td are two parameters of the Hash function pair;

select a random number r′;

determine a dynamic authentication I v ;

select a random number s and random exponents s i and s v ;

determine cipher texts C 0 =g s , C i,1 =g bs i , C i,2 =(g b 2 I i h b ) s i , C v,1 =g bs v , and C v,2 =(g b 2 I v h b ) s v ; and

determine the session key key1 of the offline data and the proxy cipher text ict of the offline data,

wherein, n denotes a count of revoked users, I i ∈u, i∈[n], n=|S ori |, I v =UCHash(chk, I ori,1 ∥ . . . ∥I ori,n , r′), UCHash denotes a chameleon hash function, s∈Z p , s i ∈Z p , s v ∈Z p , key1=e(g,g) αs , and ict=(key1, C 0 , (C i,1 , C i,2 ) i∈[n] , C v,1 , C v,2 , S ori , I v , (s i ) i∈[n] , s v , s, chk, td, r′).

10. The system of claim 9 , wherein the at least one hardware processor is further directed to:

obtain a second revocation set S={I 1 , . . . , I |S| };

determine I mall,i =(I i −I ori,i )·s i ;

determine a cipher text r; and

determine the session key key2 of the online data and the proxy cipher text ct of the online data,

wherein i∈[|S|], r=UColl(td, I ori,1 ∥ . . . ∥I ori,|S| , r′, X), UColl denotes a collision has function, X=C 0 ∥{C i,1 ∥C i,2 } i∈[|S|] ∥C v,1 ∥C v,2 ∥{I mall,i } i∈[|S|] , key2=e(g,g) αs , and ct=(C 0 , (C i,1 , C i,2 ) i∈[|S|] , C v,1 , C v,2 , {I mall,i } i∈[|S|] , chk, r).