SEC Rule 17a-4(f) governs how broker-dealers preserve electronic records, for a period of not less than six years. Since the 2022 amendments it offers two pathways. A firm may either preserve the records exclusively in a non-rewriteable, non-erasable format, the write-once approach, or preserve them in a manner that maintains a complete time-stamped audit trail that includes all modifications to and deletions of a record, and the date and time of every action that creates, modifies, or deletes it.
CFTC Rule 1.31 runs parallel for derivatives records entities. It requires systems and controls that ensure the authenticity and reliability of electronic regulatory records, and that keep them readily accessible for the required period. Both regimes turn on one question: can the record be shown to be authentic and unaltered.
The audit-trail pathway requires the trail to be complete and time-stamped, but its own integrity rests on the firm's recordkeeping system, and on the firm not altering the store beneath it. An examiner reviewing the records is, in the end, trusting that system. The write-once pathway hardens storage but ties the firm to specialized immutable media. Neither gives an outside examiner a way to check the audit trail without relying on the firm's own systems.
The rule already asks for a complete, time-stamped audit trail. Hash-chain those entries, so each commits to the one before it, and write the head of the chain as a leaf into a public transparency log at log.markovianprotocol.com, an append-only log outside the firm's control. Seven independent witnesses, including Geomys and Google's transparency.dev witnesses, cosign the log checkpoint hourly, and checkpoints are anchored to Bitcoin via OpenTimestamps. An examiner recomputes the chain from the records, which needs nobody, then checks inclusion of the head in the witnessed log from public endpoints. Once the checkpoint is anchored to Bitcoin, the head is checkable against the Bitcoin blockchain itself, independent of Markovian too.
An edit to any historical entry breaks the chain and no longer matches the anchored head. This does not replace the firm's recordkeeping, it makes the audit trail the rule already requires independently checkable, against a log the firm does not control and whose history is countersigned by independent witnesses.
Keeping a record is one thing, getting it admitted is another. Federal Rule of Evidence 902 lets certain records authenticate themselves, so they come in without a live witness to sponsor them. 902(13) covers a record generated by an electronic process or system that produces an accurate result, on a qualified person's certification. 902(14) covers data copied from an electronic device or file, authenticated by a hash or other reliable digital identification. Both were written so an opponent cannot force a records custodian onto the stand to prove that a machine-made record is what it claims to be.
An anchored audit trail maps onto both directly. The anchored hash is the reliable digital identification 902(14) contemplates, and deterministic recomputation of the chain is the accurate process 902(13) turns on, reproducible by anyone. The strength an external anchor adds is that the existence-in-time claim survives even if the firm, its systems, and its counsel are long gone by the time the record is offered. An examiner or a court recomputes against Bitcoin, not against the producer's testimony. That is the property self-authentication was built around, made checkable rather than asserted.
The same art12_audit_trail.py mechanism applies to a broker-dealer audit trail. Each entry records the action on the record, the time, and a link to the entry before it. The chain head is anchored to Bitcoin and verified by recomputation.
Markovian provides the tamper-evidence and verifiability layer on top of the audit trail the rule already requires. It proves a record was not altered and existed at a point in time, not that the underlying data was correct. Storage, retention, producing records, and any admissibility determination stay the firm's and its counsel's, and this is not a 17a-4, 1.31, or evidence-law compliance solution or legal advice.