| --- |
| license: cc0-1.0 |
| pretty_name: Sigstore Rekor subject-digest bloom filter |
| tags: |
| - bloom-filter |
| - file-hashes |
| --- |
| |
| # Sigstore Rekor subject-digest bloom filter |
|
|
| Membership filter over sha256 subject digests recorded in the |
| [Sigstore Rekor](https://docs.sigstore.dev/logging/overview/) |
| transparency log (public dataset extract, 2026-08-01) — artifacts |
| that have been signed/attested via Sigstore. |
|
|
| - **8,202,977 sha256 keys** (lowercase hex), p = 1e-4, 19 MiB |
| - A hit means "something signed an artifact with this digest"; |
| resolve against the live Rekor API for the actual log entry |
|
|
| ## Rebuild |
|
|
| See `EXTRACT.md` (BigQuery free-tier queries) + `bq_download.py` + |
| `./dcso_bloom_build.py rekor.sha256.bloom sha256 *.hex`. |
|
|
| ## Format |
|
|
| DCSO bloom filter format (`github.com/DCSO/bloom`), the same format |
| CIRCL publishes hashlookup in: 48-byte little-endian u64 header |
| (version, n, p, k, m, N) followed by the bit array. Keys are hex |
| digest strings — **UPPERCASE for sha1, lowercase for sha256** (the |
| hashlookup convention). Any DCSO-compatible reader works. |
|
|
| Membership answers are probabilistic: p = 1e-4 false-positive rate, |
| no false negatives. Confirm anything important against the source. |
|
|
