- A Software-Defined Radio Receiver for APCO Project 25 Signals A paper describing the OP25 receiver and the impact of SDR on public-safety communications.
- Eric Ramsey's Thesis-- details the Project 54 implementation using PC soundcard and analog FM radio.
- RUXCON 2010 Presentation An introduction to the basics of software-defined radio using GNURadio and OP25. Also discusses some of the security flaws present in P25 and show how these can be exploited to conduct targeted denial-of-service attacks and key-recovery attacks.
- RUXCON 2011 Presentation Sequel to the RUXCON 2010 talk with a focus on the cryptographic and authentication based security flaws that were published in the Securecomm 2011 paper.
- Security Weaknesses in the APCO Project 25 Two-Way Radio System Paper from UPenn on P25 security.
- Why (Special Agent) Johnny (Still) Can't Encrypt The UPenn paper presented at USENIX Security 2011 describing sub-frame jamming attacks.
- Insecurity in Public-Safety Communications: APCO Project 25 Paper from SecureComm 2011 on other P25 security flaws.