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 installing or maintaining a PJON network, extreme care must be taken to avoid any danger. If devices are connected to AC power you are exposed to a high chance of being electrocuted if hardware is not installed carefully and properly. If you are not experienced enough ask the support of a skilled technician and consider that many countries prohibit uncertified installations. When a SoftwareBitBang bus is installed interference mitigation and protective circuitry guidelines must be followed. When working with an AnalogSampling LED or laser based setup safety glasses must be worn and transceivers must be operated cautiously to avoid potential eye injuries. Before any practical test or a hardware purchase for a wireless OverSampling, ThroughSerial or ThroughLoRa radio setup, compliance with government requirements and regulations must be ensured.

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.