This talk illustrates an interesting application of Erlang; specifically, one dealing with analysis of encoded data in a static context. The root problem is one of analysis of data streams. In many cases, devices may wish to monitor streams of data for interesting patterns, but such analysis engines may be limited in the complexity of operations supported for such analysis. A practical example of this is a common one: a network intrusion detection system may wish to analyze email messages without having to store and forward each message. Many email systems encode binary data using the Base64 transform, a bitwise encoding scheme. For performance reasons, it is sometimes desirable to not first decode the message before analyzing its contents. This paper presents a tool, b64re, that analyzes a regular expression and transforms it such that it will now match its input when said input has been encoded using Base64. Several features of Erlang/OTP are illustrated, including parsing, the ease with which bitwise data can be manipulated, using multiple distributed processes to speed calculation, and the use of Erlang as a language in contexts other than distributed, soft real-time applications.