%0 Journal Article %T CPK Public Key and Its Basic Functions %A Xianghao Nan %J Open Access Library Journal %V 9 %N 1 %P 1-12 %@ 2333-9721 %D 2022 %I Open Access Library %R 10.4236/oalib.1108287 %X This paper introduces the working principle of CPK (Combined Public Key) and the general method of constructing identifier-based public key, which can not only solve the problem of key distribution, but also solve the authentication problem of identifier claimed by the subject. As basic functions, identifier authentication, identifier password, digital signature and key encryption are introduced. Where Identifier authentication is a new concept, and a separate authentication protocol is formulated to prove the authenticity of identifier. Identifier password is an asymmetric password, constructed with identifier authentication technique which can not only identify the authenticity of password, but also prove the authenticity of the subject, and prevent illegal access and DOS attacks. Digital signature is based on identifier authentication, which makes DSS become the digital signature standard in real sense. The key encryption implements encrypted communication between any two points on the open public network, reducing the closing segmentation granularity to the sender and receiver, making the extra regional segmentation redundant. %K Authentication %K Digital Signature %K Password %K Encryption %U http://www.oalib.com/paper/6767719