3How a result becomes a sealed record
One record from the demo sequence, record 6 of SEQ-0914-02, in seven steps from the instrument run to its place in the record history. Every value shown is computed from the signed demo data when the site is built.
-
3.1Captured
Injection 06 on HPLC-02. The chromatography data system (CDS) integrates the peak at 4.82 min, and its area, 1508811 counts, becomes the value of record 6, with four more fields: the instrument, the measurement type, the unit and the capture time.
Fig. 2.1
Captured
Simulated · demo data
Injection 06illustrative trace
4.82 min Area 1508811 countsRecord 6 · five fields
- Instrument
- HPLC-02
- Measurement
- hplc
- Peak area
- 1508811
- Unit
- counts
- Captured (UTC)
- 2026-09-14
T08:47:50Z
Fig. 2.1 · Injection 06 on HPLC-02, an illustrative trace. The shaded peak at 4.82 min has an area of 1508811 counts, the value of record 6; with four more fields it forms the record. -
3.2Fingerprinted
The five fields are joined by a vertical bar into one line of 48 bytes:
HPLC-02|. SHA-256 turns that line into a 64-character fingerprint, r6. One changed character gives a completely different fingerprint.hplc| 1508811| counts| 2026-09-14T08:47:50Z Fig. 2.2
Fingerprinted
Simulated · demo data
Record 6 · five fields
- Instrument
- HPLC-02
- Measurement
- hplc
- Peak area
- 1508811
- Unit
- counts
- Captured (UTC)
- 2026-09-14
T08:47:50Z
Payload · five fields · 48 bytes
HPLC-02|hplc|1508811|counts|2026-09-14T08:47:50Z
SHA-256Fingerprint r6
eb1690bc5922a312d90ee139fdf8e20b92bf2cb0feae8ee0e70bd24fbd2b54d7
Fig. 2.2 · The five fields joined by bars, 48 bytes, and their SHA-256 fingerprint r6, shown in full. -
3.3Signed
The fingerprint is signed with the demo key (ECDSA P-256, key id 7A15F562…), and anyone with the public key can check that the signature covers this fingerprint and no other.
Demo signature. In the alpha, one server key signs imported rows; per-analyst signatures are upcoming.
Fig. 2.3
Signed
Simulated · demo data
Record 6 · five fields· signed
- Instrument
- HPLC-02
- Measurement
- hplc
- Peak area
- 1508811
- Unit
- counts
- Captured (UTC)
- 2026-09-14
T08:47:50Z
Payload · five fields · 48 bytes
HPLC-02|hplc|1508811|counts|2026-09-14T08:47:50Z
SHA-256Fingerprint r6
eb1690bc5922a312d90ee139fdf8e20b92bf2cb0feae8ee0e70bd24fbd2b54d7
ECDSA P-256Signature · over r6 · demo key 7A15F562…
fd3cfca2c73346e6…6cadf2dfeb420279valid
Fig. 2.3 · The fingerprint signed with the demo key 7A15F562…: the signature is valid and the record’s ring is drawn; its dot fills once the record is linked. -
3.4Linked
Record 6 also stores the link of record 5, h5. Its own link is h6 = SHA-256(h5 + r6 + “6”), and record 7 carries h6 forward as its previous link. So every record is tied to the one before it, back to the fixed start value of 64 zeros.
Fig. 2.4
Linked
Simulated · demo data
Sequence SEQ-0914-02
h5h6- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
simulated anchor: h8 0a35688a…
h6 = SHA-256(h5 c04af03f… + r6 eb1690bc… + “6”) = c427b83a…
Fig. 2.4 · Records 1 to 8, each linked to the one before. Record 6 takes in h5 and passes h6 on to record 7; signed and linked, it is sealed, and its dot fills. -
3.5A change shows
Suppose the peak area is changed after sealing, from 1508811 to 1508911: the recomputed fingerprint differs from the stored r6, the signature fails and the link into record 7 breaks, while records 7 and 8 still pass their own checks. So a changed value fails that record’s fingerprint and signature and breaks only the link into the next record. Replayed from 64 zeros, the head (the newest record’s link) no longer matches the anchored fingerprint, which is simulated here.
Values in full
- Recomputed fingerprint of record 6
3cafb26418ae173c328561dcc93084e7deec8bf90d91256182d563b673a554b2- Recomputed link h6
9b5c58aa6abab7daa23c1f4e53775232309c59ee360fa24342e2888fadcd8a86- Link h6 that record 7 carries
c427b83a4e29adf9380bef67d00302e12ddfd558ae8f5a558547b2b0cf3cba23- Replayed head
75d3969cb8e256fdaa255eeaf895a3c57ec59e4ad68158850a6731bfb9cd05d3- Simulated anchor, h8
0a35688a4c3ec82a5e621cede1f173a6d436ade0e20f159dca92c2a3711e3dc1
Fig. 2.5
A change shows
Simulated · demo data
Record 6 · sealed· changed after sealing
- Instrument
- HPLC-02
- Measurement
- hplc
- Peak area
- 15088111508911
- Unit
- counts
- Captured (UTC)
- 2026-09-14
T08:47:50Z
Payload · five fields · 48 bytes
HPLC-02|hplc|15088111508911|counts|2026-09-14T08:47:50Z
SHA-256Fingerprint r6Fingerprint, recomputed≠ stored r6 eb1690bc…
eb1690bc5922a312d90ee139fdf8e20b92bf2cb0feae8ee0e70bd24fbd2b54d73cafb26418ae173c328561dcc93084e7deec8bf90d91256182d563b673a554b2
ECDSA P-256Signature · over r6 · demo key 7A15F562…
fd3cfca2c73346e6…6cadf2dfeb420279validfails
Sequence SEQ-0914-02
h5h6 ≠- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
simulated anchor: h8 0a35688a…replayed head 75d3969c… ≠ simulated anchor 0a35688a…
h6 = SHA-256(h5 c04af03f… + r6 eb1690bc… + “6”) = c427b83a…
link 6→7 broken: recomputed h6 9b5c58aa… ≠ c427b83a… · records 7 and 8 pass
Fig. 2.5 · The peak area changed to 1508911: the recomputed fingerprint differs, the signature fails, link 6→7 breaks and the replayed head no longer matches the simulated anchor. Records 7 and 8 pass their own checks. -
3.6A correction is appended
Made the right way, the same change is a correction: record 6 stays as sealed, and a new record 9 holds the new value, 1508911, with its own fingerprint, a link from record 8 and a signature. Its reason (“Peak reintegrated in the CDS after review; result imported again”) and “corrects #6” sit beside the seal, not inside it; all 9 records pass, and the new head, h9, is not yet anchored.
Record 9 is signed with a one-time demo key (key id FEE1BE86…), made at build and then discarded, as Check a record signs a correction with a one-time demo key made in your browser; the demo key that signed records 1 to 8 was discarded too, so it cannot sign anything new.
Values in full
- Fingerprint r9 (the same five fields as the change, so the same fingerprint)
3cafb26418ae173c328561dcc93084e7deec8bf90d91256182d563b673a554b2- Link h9
128206a058f6bf9d72741d670e5ecd966c4eacfadc54137a4871a694d7a393aa- Signature of record 9
cb757702b66cf3984809b7c1c1dfb71f4731a5bf6526a4b43893aa95e89c207574cddb19cc97b97d2c40b1a82a33a85d249af2c721a58e26c5e053003ac985b3- One-time public key (uncompressed point)
040d586f9eeccc0c9e711002279871b277cca37e8bf05d52610d0415e044dcbfc8e9bb9c57500c81dd5dec6b1276a414a899f9e0a962eab91a9854841f07dbf817- Its key id (first 16 bytes of SHA-256 of its SPKI)
FEE1BE866091FC4D427FD85C383BDCA1
Fig. 2.6
A correction is appended
Simulated · demo data
Record 6 · stays as sealed · peak area 1508811
Record 9 · other fields as in #6 · one-time demo key FEE1BE86…
- Peak area
- 1508911
- Fingerprint r9
- 3cafb264…
- Link h9
- 128206a0…
- Signature
- cb757702b66cf398…c5e053003ac985b3 valid
Beside the seal: corrects #6 · reason “Peak reintegrated in the CDS after review; result imported again”
Sequence SEQ-0914-02
h5h6corrects #6- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
simulated anchor: h8 0a35688a…simulated anchor matches records 1 to 8 · record 9 not yet anchored
h6 = SHA-256(h5 c04af03f… + r6 eb1690bc… + “6”) = c427b83a…
h9 = SHA-256(h8 + r9 + “9”) = 128206a0… · all 9 records pass
Fig. 2.6 · Record 6 stays as sealed. Record 9 holds the new value with its own fingerprint, a link from h8 and a signature with a one-time demo key; its reason and “corrects #6” sit beside the seal. All 9 records pass, and record 9 is not yet anchored. -
3.7What comes next Upcoming
Upcoming: the head of a batch, here h8, written to a public network. Only that fingerprint would go on the network, never the values. Upcoming too: an AI agent that checks fingerprint, signature, link and anchor before it uses a result.
Fig. 2.7
What comes next
Simulated · demo data
Public network Upcoming
h8 0a35688a…
Only this fingerprint would go on the network, never the values.
AI agent Upcoming
- Fingerprint
- Signature
- Link
- Anchor
It would check all four before it uses a result.
Sequence SEQ-0914-02
corrects #6- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
simulated anchor matches records 1 to 8 · record 9 not yet anchoredh8 0a35688a…, the head of records 1 to 8
h9 = SHA-256(h8 + r9 + “9”) = 128206a0… · all 9 records pass
Record 9 would go in the next batch.
Fig. 2.7 · Upcoming: h8, the head of records 1 to 8, written to a public network, and an AI agent that checks fingerprint, signature, link and anchor. Nothing here touches a network.