Publicaciones
Deterministic Sovereign RAG
Period: Aug 2025 —
The challenge
Most retrieval-augmented generation pipelines are non-deterministic across re-runs, so an audit cannot trace which evidence supported which generated claim. The 'retrieval' half of RAG is a black box.
My role
I published the math foundation for O(1) local context compaction: FNV-1a 128-dim projection, L2 normalization, cosine similarity, with Chernoff-Hoeffding concentration bounds. The work anchors a companion repository and a meta-tool.
What I did
01 Deterministic projection of context windows
Why: A 128-dimensional FNV-1a projection collapses a context window to a fixed-size vector that is reproducible across runs. The projection is O(1) per token and round-trip safe.
Trade-off: FNV-1a is not cryptographically secure; the projection is for similarity scoring, not for tamper resistance. Cryptographic anchoring is a separate layer.
02 Concentration bounds make the similarity claim auditable
Why: A cosine similarity above a threshold is not by itself a claim; the Chernoff-Hoeffding bound makes it a claim with a confidence interval. Auditors get a number, not a vibe.
Trade-off: The bounds are conservative — a relevant document that would pass a looser threshold can fail the bound. The discipline is the point.
03 Local-first execution end to end
Why: The projection runs in-process; the embeddings never leave the operator's machine. The sovereign-rag posture is the design constraint, not a marketing line.
Trade-off: CPU cost is on the operator. The cost is the price of an audit chain that does not depend on a third-party embedding service.
What changed
Context compaction
Before: Variable window, non-reproducible
After: Fixed 128-dim projection, deterministic
Audit confidence on a similarity claim
Before: Vibes, no bound
After: Chernoff-Hoeffding confidence interval
Operator-controlled execution
Before: Hosted embedding API
After: Local-first, in-process
Trade-offs
The deterministic posture costs CPU. A reviewer who does not need the audit chain can use a hosted embedding service and skip the projection entirely.
What I learned
Determinism is not the same as security; determinism is the precondition for an audit chain to exist at all.
Stack
- Math
- FNV-1a
- L2 normalization
- Chernoff-Hoeffding