A Collusion-Resistant and Privacy-Preserving Data Aggregation Protocol in Crowdsensing System

Algorithm 1

Enc&Sign.

Input:

For each user , input his/her pseudo ID , secret encryption key set , and secret signing key .

Each user uploads his/her data in the time period .

The symbol represents the concatenation of and and denotes the exclusive-or of all the results of

function for each element in .

Output:

The user outputs and as follows:

begin

 () Generate random -bit strings using

 () The data is encrypted as:

 () The signature is computed as:

 () Output and .

end