Generalization of Proxy Signature Based on Factorization

Digital signatures are widely used to replace hand-written signatures in the digital world. However, simple digital signature schemes are not enough to satisfy today's practical conditions. For example, suppose a chairman in a department needs to go on a business trip. She/He has to find a proxy person to deal with her/his work at the office. Traditional digital signature schemes do not meet this requirement. To remedy this weakness, the proxy function has been added to digital signature schemes, and this new type of digital signature is called proxy signature.