Anonymous Evaluation System 

           Lucjan Hanzlik, Kamil Kluczniak, Przemyslaw Kubiak, Miroslaw Kutylowski 
		    Faculty of Fundamental Problems of Technology
                       Wroclaw University of Technology

We present a pragmatic evaluation system, where privacy of each evaluator is guaranteed in 
a cryptographic way. Each evaluation report is signed with a domain signature that is related 
to the anonymous signer and to the  evaluation subject in the way that

(a) a given user cannot appear under different pseudonym for a given evaluation subject 
(no Sybil attack possible), 

(b) it is infeasible to decide whether the signatures for different subjects have been created 
by the same evaluator, 

(c) each evaluator holds a single private key. 

Unlike available anonymous credential systems and domain signatures proposed so far, our scheme 
is based on standard operations available on most cryptographic smart cards and easy to implement 
in the scenarios where the set of evaluators is determined. We describe one application scenario  -- 
a university  evaluation system with courses feedback from the students. 

                       
KEYWORDS: anonymity, authentication, domain specific pseudonym, digital signature,  unlinkability, 
white list


ACCEPTED FOR: 9th International Conference on Network and System Security (NSS) 2015, New York