The access control provided by a physical lock is based on the assumption that the information content of the corresponding key is private -- that duplication should require either possession of the key or a priori knowledge of how it was cut. However, the everincreasing capabilities and prevalence of digital imaging technologies present a fundamental challenge to this privacy assumption. Using modest imaging equipment and standard computer vision algorithms, we demonstrate the effectiveness of physical key teleduplication -- extracting a key's complete and precise bitting code at a distance via optical decoding and then cutting precise duplicates. We describe our prototype system, Sneakey, and evaluate its effectiveness, in both laboratory and real-world settings, using the most popular residential key types in the U.S. Categories and Subject Descriptors I.4.7 [Image Processing and Computer Vision]: Feature Measurement General Terms Experimentation, Measurement, Security Keyword...