A special signature is a signature written by the author himself. Special signature means that when a book is published, the author will add a sentence related to the content of the work in addition to his own name. Such signatures often have special significance and value. Special signature plays a vital role in the digital world, especially in protecting information security and personal privacy. This signature allows the original sender of the message to sign without revealing the content of the message. In the blind signature process, the signer can only get the hash value of the message, but can't see the actual content of the message. This signature method has good privacy protection characteristics, and is often used in scenes that require confidentiality and anonymity, such as electronic voting and electronic cash.