The lack of a trusted authority, responsible for peers' identity verification or for authentication purposes, makes actual P2P systems extremely vulnerable to a large spectrum of attacks. The main purpose of this paper is to present Likir (Layered Identity-based Kademlia-like InfRastructure), a framework that includes an identity-based scheme and a secure communication protocol, built on top of Kademlia, that may provide an effective defense against well known attacks. This will be accomplished with the adoption of a certification service, with the use of an authentication protocol between nodes and with the introduction of credentials to make non-repudiable the ownership of the contents and messages inserted in the DHT. For sake of interoperability with other social networking services, Likir enables identity management under the Identity 2.0 framework. Under this perspective, the IBS (Identity-Based Signature) scheme is taken into consideration and analyzed as well.