Data protection is an increasingly important issue in today’s communication networks. Traditional solutions for protecting data when transferred over a network are almost exclusively based on cryptography. As a complement, we propose the use of multiple physically separate paths to accomplish data protection. A general concept for providing physical separation of data streams together with a threat model is presented. The main target is delay-sensitive applications such as telephony signaling, live TV, and radio broadcasts that require only lightweight security. The threat considered is malicious interception of network transfers through so-called eavesdropping attacks. Application scenarios and techniques to provide physically separate paths are discussed.