In the Electronic Health Record system

users update their health data frequently.If users keep the authentication of these data with the signature scheme in existence

it will lead to the leakage of their identity privacy and huge computation cost.Aiming at tackling the problems above

we propose a novel scheme called attribute-based sanitizable signature supporting dendritic access structure which obfuscates the user identity with attribute sets and introduces an authorized semi-trust third-party-sanitizer.The security analysis demonstrates that our scheme achieves the anonymity of users and is unforgeable under selective-predicate chosen-message attack in the standard model.Through comparison

our scheme not only reduces the signing computation overhead of users

but also supports the dendritic access structure which can provide flexibly fine-grained access control under large-scale attribute sets.