Measurable Security through Isotropic Channels

Abstract

This position paper proposes the use of special broadcast networks to achieve provable and measurable confidentiality of messages. We call these networks isotropic channels, broadcast channels in which receivers cannot reliably determine whether a given message originated from any particular sender and senders cannot prevent a message from reaching any particular receiver. As long as eavesdroppers cannot reliably (i.e., with probabilistic certainty) identify the sender of a message, honest parties can efficiently exchange messages with confidentiality that asymptotically approaches and in some cases reaches perfect secrecy. Even under incorrect assumptions regarding the degree of isotropism offered by a particular channel, a high measure of confidentiality can be efficiently achieved.

This position paper additionally makes the case that isotropic channels already exist, and are, in fact, often used in practice. By leveraging isotropic techniques, measurable information theoretic security can be practically achieved.