Information hazards and safe redaction

Subjective information hazards present a unique challenge within blockchain ecosystems. Although there is no consensus on a universal, objective list of such hazards, it is widely acknowledged that these risks exist and can be perceived differently depending on individual perspectives. The immutable nature of blockchain technology raises the possibility that any form of information hazard could be recorded permanently on-chain, with no effective or general defense currently available to prevent this outcome. For some users, these hazards are already present in today’s blockchains, while others see the risk as a future concern.

Users who wish to avoid storing or propagating such information hazards face limited options. Existing solutions typically involve trusting third parties or relying on community-driven mechanisms for managing data, such as backing up blockchains, sharing unspent transaction output (UTXO) data, or validating blocks. These approaches do not offer granular control over what data is retained or redacted, especially for those looking to operate full archival nodes without perpetuating undesired content.

There is a pressing need for tools or protocols that enable users to safely redact information hazards from their local copies of the blockchain. Such solutions should preserve as much core functionality and benefit of running an archival node as possible, while empowering users with the ability to exclude data they personally deem hazardous. The current landscape lacks active development in this area, despite prior research efforts. Engagement and collaboration are encouraged, particularly among individuals or groups exploring or interested in this aspect of blockchain data management.

It is important to note that the focus is on empowering users to manage information hazards locally, rather than imposing restrictions on what data can be published in new blocks. While limiting arbitrary data publication might offer some protection, this approach falls outside the intended scope. A related but less complex issue involves unconfirmed transactions in the mempool, where information hazards can also appear. However, these are easier to address since users can more readily reject, drop, or refuse to share unwanted transactions before they are mined into the blockchain.