Decisional composite residuosity assumption
Introduction The '''decisional composite residuosity assumption (DCRA)''' is a mathematical assumption used in cryptography. In particular, the assumption is used in the proof of the Paillier cryptosystem.Informally, the DCRA states that given a composite  and an integer , it is hard to decide whether  is an -residue modulo . ''I.e.'' whether there exists a  such that:
See also * Quadratic residuosity problem* Higher residuosity problem
References * P. Paillier, ''Public-Key Cryptosystems Based on Composite Degree Residuosity Classes'', Eurocrypt 1999.