document: Enhancing the privacy of web-based communication A profiling adversary is an adversary whose goal is to classify a population of users into categories according to messages they exchange . This adversary models the most common privacy threat against web based communication . We propose a new encryption scheme , called stealth encryption , that protects users from profiling attacks by concealing the semantic content of plaintext while preserving its grammatical structure and other non-semantic linguistic features , such as word frequency distribution . Given English plaintext , stealth encryption produces ciphertext that can not efficiently be distinguished from normal English text ( our techniques apply to other languages as well ) .
doc_bio_tags: O O B O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O