Recently, as network and conputing power make rapid progress, a researches for giving reliability to
data through network are being increased. In particular, public key infrastructure (PKI) that performs
a function of confirming personal information and prevent Counterfeit and modification has been
rapidly developed based on an certificate. However, The PKI shows some problems for certificate
authority (CA), user, and Domain Name Server (DNS). The PKI problems are also represented in
security as well as in cost and authentication environment. In addition, in order to process certificate,
existing PKI system used certificate authority (CA) that is a hierarchical structure. Therefore, in this
study, PKI framework based on certificateless that uses hierarchical identifier by using DNSSEC
applying security to existing DNS is proposed. This framework could reduce cost incurred by existing
certificate and supplement existing vulnerability.