In real life, one requires signatures to be from people who should possess specific atribtutes. For example, Alice might wants a document to be signed by an employee in Bob company who possess specific attributes. For this purpose a multi-authority attribute-based signature is introduced that only the signature of the person who has the desired pecific attributes is confirmed. The multi-authority attribute-based signature is one of the applications of attribute-based encryption. In this signature, the identity of the signer is confirmed based on its attributes, each of which is under the supervision of a authority. In this scheme, in addition to preserving the personal identity of the signer, the attributes that he used in signing his message are also hidden. Since a blockchain structure has significant features such as preserving the identity of the signer, decentralized structure, and data retention without a secure data center, in this dissertation we try to introduce multi-authority attributebased signature in the blockchain structure and show its application in the electronic health registration system. In this scheme, data is stored in a block without the need for a secure data center. The user also gains the ability to perform certain tasks, such as receiving or sending messages or accessing information sources, based on his atribtutes, each of which is supervised by a authority. By providing this signature in a blockchain environment, conditions are created in which a user who has certain attribute can access the information of each block in a peer-to-peer network without the need for an intermediate person.