The Blue Safe Box is both a black box (recorder) and external hard drive, which includes specific programs & subroutines from the Droid Enforcement & Safety Agency (DES) in the Kingdom of Jod. These programs and subroutines are typically antivirus updates, system updates, and security updates; droids' recharge couplings were routed through the Blue Safe Box itself, which prevented charging of the droid without the Blue Safe Box installed, as well as uploading of any computer viruses through the recharge system without being filtered through the Blue Safe Box's security systems first.
The Blue Safe Box is required to be uploaded to a DES Monitoring Site yearly, with a new Blue Safe Box given each year; old Blue Safe Boxes are wiped clean of data, physically updated with parts where needed, and recycled for use for up to 4 years, then permanently destroyed. Owners are required to deliver their droids to DES Monitoring Sites---or allow DES Technicians access to homes & businesses---on demand of DES if urgent & immediate updates are needed on Blue Safe Boxes, which do happen at least every other month, sometimes more frequently depending on threats to the droids' systems.
The Blue Safe Box is a closed system, communicating with and transferring data to the droid brain of a droid and back to the Blue Safe Box with no way to extract the data and information from the Blue Safe Box---or otherwise change any of the data and information---legally & safely, without triggering the dead man's switch from the Blue Light Safety Droid System (BSD). The closed system nature of the Blue Safe Box prevents a computer virus or other sabotage method from violating the droid's system, like what happened with the Droid Crisis of 33 BBY.