Chaffing and Winnowing: Confidentiality without Encryption

Header hopping and packet mixers

We describe a steganographic protocol for packet switched networks that is based on the dynamic rewriting of packet headers. The protocol provides confidentiality without encryption based on Rivest’s “chaffing and winnowing” technique. We identify new places in computer networks where this method can be applied and describe an alternate chaffing method that relies on unpredictable number sequen...

Confidentiality without Encryption For Cloud Computational Privacy

Advances in technology has given rise to new computing models where any individual/organization (Cloud Service Consumers here by denoted as CSC's) can outsource their computational intensive tasks on their data to a remote Cloud Service Provider (CSP) for many advantages like lower costs , scalability etc. But such advantages come for a bigger cost “Security and Privacy of data” for this very r...

Chaffinch: Confidentiality in the Face of Legal Threats

We present the design and rationale of a practical system for passing confidential messages. The mechanism is an adaptation of Rivest’s “chaffing and winnowing”, which has the legal advantage of using authentication keys to provide privacy. We identify a weakness in Rivest’s particular choice of his “package transform” as an “all-or-nothing” element within his scheme. We extend the basic system...

Unconditionally secure chaffing and winnowing with short authentication tags

The Security of Chaffing and Winnowing

This paper takes a closer look at Rivest’s chaffing-and-winnowing paradigm for data privacy. We begin with a definition which enables one to clearly determine whether a given scheme qualifies as “chaffing-and-winnowing.” We then analyze Rivest’s schemes to see what quality of data privacy they provide. His bit-by-bit scheme is easily proven secure but is inefficient. His more efficient scheme —...