The Hash Box – An Introduction

In future nuclear arms control inspections, digital information, e.g., photographs, may be collected to support inspections. This data will likely need to be reviewed by the host before it is released to the inspectors, particularly if the inspection is at a nuclear weapons facility. The inspectors will need to confirm that the data has not been altered to have confidence in the data. Furthermore, the host must be able to redact data before it is released to the inspector to protect sensitive information. An approach was proposed in 2021 to address these concerns by computing simple cryptographic hashes of the data. In this method, hashes of the data are combined into a single root hash that can be reported and confirmed by all parties. In case of redaction, the host can provide the hash(es) of the removed data to enable the inspector to confirm the released data. In addition, the relatively simple implementation resulted in an inexpensive device; on the order of $100. This paper will discuss the approach as well as how it has been implemented on a prototype device.