Explore the latest developments in Software-Defined Radio (SDR) and toll booth reverse engineering in this 58-minute conference talk from BSides Columbus 2019. Delve into the E-Z Pass system, comparing protocols and examining interoperability updates. Learn about the original challenge, FCC ID identification, and specification hunting. Gain insights into key communication sequences, frequencies, and modulation types like On-Off Keying (OOK) and Manchester encoding. Discover essential tools and understand IQ data, GNU Radio, and FFT analysis. Investigate reader transponder strength complications, packet processing, and dissection techniques. Examine amplitude modulation from a transmitter perspective and explore original readers. Discuss potential attack vectors, the importance of this research, and the future of toll groups in the US. Conclude with valuable lessons learned and participate in a Q&A session.