Methods and systems are provided for improving security, efficiency, access control, administrative monitoring, reliability as well as integrity of data transmission and remote application sharing over a network. Secure, stable network connections and efficient network transactions among multiple users are supported by an improved client-server architecture. A datagram schema is provided, which enables dynamic datagram switching in support of a multitude of applications and network services. Mobile intelligent data carriers are provided, allowing for the implementation of an authentication and encryption scheme. They may be used to target deliver applications to authorized user, thereby controlling the access to not only data but also applications. Biometrics and other suitable authentication methodologies may be employed in delivering the pervasive, user-centric network security solutions disclosed. The methods and systems of this disclosure maybe advantageously implemented in any enterprise network environment to support a wide spectrum of business, research, and administrative operations.