The tamper-evident grade platform. Every record is sealed with a SHA-256 content hash, chained to its predecessor, and signed with the faculty member's RSA-2048 key — so a silent database edit breaks the chain, and the break is provable.
Chain health
100%
All blocks verified
Total records
8
Chain status
Verified
Flagged entries
0
Registered signers
3
| Block | Student | Course | Grade | Status |
|---|---|---|---|---|
| #1 | Rafiq Ahmed | CSE 323 | B+ | VERIFIED |
| #2 | Nusrat Jahan | CSE 315 | A | VERIFIED |
| #3 | Tanvir Islam | CSE 208 | A- | VERIFIED |
| #4 | Farhana Akter | CSE 323 | B | VERIFIED |
Products
Every grade is a block: a deterministic canonical payload, reduced to SHA-256, storing its predecessor's digest. Rewriting one block invalidates every block after it.
{
"block_index": 2,
"course_id": "course-cse323",
"created_at": "2026-08-01T10:32:00Z",
"grade": "B+",
"prev_hash": "5f2a8eb1fdc3…89a2b",
"signed_by": "fac-mamun-001",
"student_id": "std-001"
}Each faculty signer holds an RSA-2048 key pair. Private keys never leave the server; every digest is signed server-side and verifiable against the registered public key.
# signature = RSA_SIGN(priv, record_hash)
RSA_VERIFY(pub, record_hash, signature) → VALID
One click replays the entire chain: recomputes every hash, checks every link, verifies every signature — and names the exact block and failed check when anything is off.
$ POST /api/verification
✓ hash_valid ✓ chain_valid ✓ signature_valid
→ STATUS: VERIFIED · 8/8 blocks authentic
A direct SQL edit — the attack this system assumes — no longer hides. The stored digest no longer matches the payload, and verification flags the record for every later block to see.
stored grade: B+ · db value: A+
✗ hash mismatch · ✗ signature invalid · FLAGGED
How the evidence works
Each block stores its predecessor's digest. Recompute any record and the mismatch propagates to every later block — the chain speaks for itself, no auditor required.
Canonical serialization
Identical content always produces an identical byte representation before hashing (NFR-03).
Sequential hash chaining
prev_hash → record_hash links every block to its predecessor, genesis to head.
Server-side verification
Authorization and signing happen exclusively on the server; keys never reach the browser.
LEDGER OPENED · 2026-08-01
CSE 323 Operating Systems · Midterm · 85
CSE 315 Database Systems · Final · 90
CSE 208 Data Structures · Quiz 3 · 78
Illustrative demo data · live verification recomputes every block at /verify
Honest limits
Beyond grades
Nothing in the chain knows what a grade is. Swap the payload and the identical hash-link-sign-verify machinery protects transcripts, research data, medical records, supply chains, and land registries.
Explore all applicationsTranscripts & degrees
Re-provable years after issuance
Research data
Lab results timestamped into the chain
Medical records
Clinician-signed patient histories
Supply chains
Custody provenance that breaks when forged
The seeded demo dataset, the tamper simulation, and the full verification runner are one click away.