Secure Storage and Retrieval of IoT Data Based on Private Information Retrieval

Algorithm 2

Token generation.

Input:(i) ⊳ The ciphertext related to the file

(ii) ⊳ The user’s public key given by PIR protocol

(iii) ⊳ The user’s secret key

(iv) ⊳ The user’s set of attributes

Let: ⊳ The set of attributes involved in

(2) Choose a set of constants ,

(3) for to do

(4) ifthen⊳ are valid shares of the secret according to

the data

(5) Reconstruct the encryption exponent:

(6) end if

(7) end for

(8) Let are random constants

(9) ifthen⊳ The user’s attributes satisfies

(10) else⊳ cannot successfully computed

(11) ⊳ will get a random Hexadecimal value

(12) end if

Output:The Decryption Token