A Note on Obtain Confidentiality or/ and Authenticity in Big Data by ID-Based Generalized Signcryption

ID based generalized signcryption can adaptively work as a signature scheme, an encryption scheme or a signcryption scheme and avoid weighty and complicated certi…cate management like Public Key Infrastructure. It has application in emerging paradigm big data security. Recently, Wei et al proposed a new ID based generalized signcryption scheme to obtain con…dentiality or/and authenticity in big data, and claimed that their scheme is provably secure in standard model. Unfortunately, by giving substantial attack, we indicate that Wei et al scheme su¤er from compromise of Private Key Generator (PKG) master secret key and thus not hold the security of indistinguishability against adaptive chosen-ciphertext attacks (IND CCA) and existential unforgeability against adaptive chosen-message attacks (EUF CMA). Key words: Cryptanalysis, Big Data, Con…dentiality, Authenticity, Generalized signcryption, Standard model