PJON is still in experimental phase and it distributed "AS IS" without any warranty, although a lot of work is iteratively done to make it more secure and reliable. Its implementation and specification are publicly available and are constantly reviewed worldwide by the community, the developers team and more recently by academics.

The security of a system that uses PJON for communication mostly depends on the vulnerabilities exposed by the hardware and by the physical layer used. Consider that only air-gapped wired local buses are undoubtely secure. When connecting a local bus to the internet using ESPNOW, EthernetTCP or LocalUDP, GlobalUDP or DualUDP, all connected devices must be considered potentially compromised. It should be considered a good practice not to connect to the internet systems that may cause damage (fire, flood, data-leak) if hacked.

When testing PJON, take extreme care to avoid any danger. The implementation is experimental and may not behave as expected; use it at your own risk. If devices are connected to AC power, you face a high risk of electrocution unless the hardware is installed carefully and correctly. If you lack sufficient experience, seek assistance from a qualified technician, and be aware that many countries prohibit uncertified installations. When testing a SoftwareBitBang bus follow interference-mitigation and protective-circuitry guidelines. When experimenting with an AnalogSampling setup, wear safety glasses and operate transceivers cautiously to prevent eye injuries. Before testing OverSampling, ThroughSerial or ThroughLoRa radio communication, ensure that the frequency, power, and hardware comply with local regulations. When connecting a local bus to the Internet, treat all devices as potentially compromised, manipulated, or remotely actuated against your will. As a best practice, avoid connecting to the internet systems that could cause damage (fire, flood, data leakage) if hacked.

If you discover a vulnerability in the specification or in the implementation please report it as soon as possible opening an issue. If you have developed a fix, feel free to open a pull request.