In the chain of the healthcare domain even in the public or private sector of a developing country, there is still much concern about information sharing, security, and privacy, especially for identity management. In Cambodia, currently, the centralized framework for identity management is mostly used, which highly depends on a single trust third-party Certificate Authority (CA) such as the General Department of ICT (GDICT) at the Ministry of Post and Telecommunication for making decisions. The identity of data is owned and managed by the service provider, so the risk might occur once the CA is hacked, the adversary could distribute false certificates with pseudo-identity. This research proposes a decentralized blockchain-based PKI for patient identification in the Blockchain network. It is decentralized, removes the need for having Certificate Authorities (CAs) and Certificate Revocation Lists (CRLs), and supports important functionalities for enrollment, verification, validation, update, and revocation of certificates. As the result, the decentralized identification model that supports the healthcare domain has been proposed in developing countries.