Paper 2019/556 Original: eprint.iacr.org/2019/556 ↗

When Encryption is Not Enough -- Effective Concealment of Communication Pattern, even Existence (BitGrey, BitLoop)

Abstract

How much we say, to whom, and when, is inherently telling, even if the contents of our communication is unclear. In other words: encryption is not enough; neither to secure privacy, nor to maintain confidentiality. Years ago Adi Shamir already predicted that encryption will be bypassed. And it has. The modern dweller of cyber space is routinely violated via her data behavior. Also, often an adversary has the power to compel release of cryptographic keys over well-exposed communication. The front has shifted, and now technology must build cryptographic shields beyond content, and into pattern, even as to existence of communication. We present here tools, solutions, methods to that end. They are based on equivocation. If a message is received by many recipients, it hides the intended one. If a protocol calls for decoy messages, then it protects the identity of the sender of the contents-laden message. BitGrey is a protocol that creates a "grey hole" (of various shades) around the communicating community, so that very little information leaks out. In addition the BitLoop protocol constructs a fixed rate circulating bit flow, traversing through all members of a group. The looping bits appear random, and effectively hide the pattern, even the existence of communication within the group.