2006 Reports

W3Bcrypt: Encryption as a Stylesheet

Stavrou, Angelos; Locasto, Michael E.; Keromytis, Angelos D.

While web communications are increasingly protected by transport layer cryptographic operations (SSL/TLS), there are many situations where even the communications infrastructure provider cannot be trusted. The end-to-end (E2E) encryption of data becomes increasingly important in these trust models to protect the confidentiality and integrity of the data against snooping and modification by the communications provider. We introduce W3Bcrypt, an extension to the Mozilla Firefox web platform that enables application-level cryptographic protection for web content. In effect, we view cryptographic operations as a type of style to be applied to web content along with layout and coloring operations. Among the main benefits of using encryption as a stylesheet are (a) reduced workload on a web server, (b) targeted content publication, and (c) greatly increased privacy. This paper discusses our implementation for Firefox, but the core ideas are applicable to most current browsers.