Systems and methods are provided for managing user information comprising presence information, wherein authentication of requesting parties is based on public-private key pair encryption and key Domain Name Service (kDNS) infrastructure. Thus, a response to a request for presence information may be dependent on the authentication status of the requesting party. Presence information stored on a presence server or other network element may be stored or updated upon receiving a request from a user which includes the requestors identify, and is signed with the private key of the requestor. After authentication of a user having a registered unique identifier and an associated public key, presence information may be stored or updated, in either encrypted or unencrypted form. Presence information is preferably stored with user specified policy information for managing access to the presence information by other users, e.g. what information may be shared with anonymous or unauthenticated other users, or with other specific authorized users, or authorized user groups. Advantageously, all communications between communication parties and network elements of the system are encrypted. A scalable and distributed system and method is provided for managing exchange of dynamic information, such as presence information, between users of communications and network services, with improved reliability, security, and personalization. Systems and methods are particularly applicable for securely managing exchange of presence information and other information for multiparty communications service and for peer-to-peer network services.