Disclosed is a universal plug-in Distributed Public Keystore (DPK) module provided on a user equipment. The DPK module approves its identifier with a Public Key Manager (PKM) and obtains cryptocurrency from the PKM. The APPs on the user equipment generate and transmit user public keys to the DPK module. The DPK module generated its own user public key as well. After a storage transaction requirement by the DPK module is approved by a blockchain, the DPK module sends obtained user public keys to the blockchain so that the user public keys are stored in the blockchain. The user public keys are never stored outside the blockchain or in a third part server. The stored user public keys are retrieved to the DPK module when necessary, such as when a P2P communication is performed by any of the APPs.