PRAMANA

Secure Digital Document Management System for Legal and Investigation Documents

Smart India Hackathon 2026 · Problem Statement 26190 Ministry of Home Affairs · National Crime Records Bureau (NCRB), Women Safety Division Category: Software · Theme: Blockchain & Cybersecurity

प्रमाण - the Sanskrit and Indian-jurisprudence term for proof, the valid means of establishing truth. It backronyms cleanly: Provenance, Retention, Access Management And Notarised Archive.

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What this is

A working prototype of the missing layer in India's criminal justice IT stack.

CCTNS records that a crime happened. eCourts records that a trial happened. Nothing owns the documents in between - their integrity, their custody, their confidentiality, their retention. PRAMANA is that layer, and it speaks ICJS at both ends.

Every document is fingerprinted and encrypted the moment it is captured, its fingerprint is anchored on a permissioned consortium ledger, every access is attribute-checked and permanently logged, every custody transfer is signed, and any file can be proved unaltered in court - by the other side, without trusting us.

New here? Read docs/PROJECT_BRIEF.md - what we are building, how the four core mechanisms work, where we stand, and what is left to finish.

Run it

Requires Node.js 22.5+ (24 recommended). No database server, no Docker, no native builds.

git clone https://github.com/Abhist17/Pramana_190.git
cd pramana
npm install
npm run seed     # builds a fictional corpus: 6 cases, 19 sealed documents, 42 ledger anchors
npm run dev      # API on :4000, console on :5173

Open http://localhost:5173. Every demonstration account uses the password pramana.

Sign in as	Who they are	What to notice
r.deshmukh	SI Rohini Deshmukh - woman officer, assigned to the sensitive cases	Can record victim statements; sees the Women Safety cases
a.pawar	SI Amit Pawar - assigned only to the general cases	Blocked from the same cases, with the rule that refused him
m.iyer	DSP Meera Iyer - district supervisor	Rank alone still does not open a Women Safety case
n.banerjee	APP Nandita Banerjee - prosecutor	Sees exactly what was shared, for as long as it was shared
d.security	CISO Divya Nair	Reads the audit trail - and has no path to case content at all

Two pages need no login: /verify (public verifier) and /citizen (case status portal).

Other commands

npm test              # 32 unit tests: Merkle, Shamir, envelope crypto, ABAC engine
npm run typecheck     # strict TypeScript across both workspaces
npm run reset         # rebuild the corpus from scratch (restart the API afterwards)
npm run build         # production build of the console

The five things worth showing

1. The tamper demonstration. Open any document → Integrity → Flip one bit. One bit changes in storage. The fingerprint anchored on the ledger does not, and cannot. Verification fails with a character-level diff of the two digests. (The original is backed up first, so it is safe to rehearse.)

2. The evidence certificate. One click produces the certificate the 2023 evidence statute requires - pre-filled with the hash and the algorithm, plus the device, the capture circumstances and the full custody history, routed for the dual signature the statute demands. The law now asks for a hash. Nobody has automated producing it. docs/LEGAL_MAPPING.md

3. Access denial you can read. Sign in as an unassigned Superintendent and open a Women Safety case. Refused - and told exactly which rule refused him and why. Rank grants nothing; explicit assignment does. The Access policy page simulates any officer against any resource and shows every rule that fired.

4. Cross-lingual search. Query witness saw a maroon vehicle near the school and the top two results are handwritten Hindi statements. Query गवाह का बयान and it works in reverse.

5. Hand over the laptop. Open /verify, let a judge drag the file in themselves. It says whether that exact fingerprint was anchored and when, and nothing about content, case or parties. Integrity stops being a claim.

A five-minute run of these is scripted in docs/DEMO_SCRIPT.md.

What is actually built

Area	Status
Capture → hash → envelope-encrypt → sign → anchor	Working, end to end
Immutable originals, version chains, renditions	Working
ABAC policy engine (17 rules, deny-by-default, version-anchored)	Working, with a simulator
Chain of custody, documents and physical exhibits	Working, signed both sides
Merkle-batched audit log with per-event inclusion proofs	Working, verifiable off-server and on-chain
Evidence certificate with dual signature + PDF	Working
Women Safety module: auto-escalation, identity vault, statutory role enforcement	Working
Sealed cover under Shamir m-of-n threshold custody	Working
Statutory deadline engine with tiered escalation	Working
Hybrid search (BM25 + dense vectors, cross-script)	Working
True redaction as a separate sealed rendition	Working
UEBA anomaly detection	Working, rules layer
Retention, legal hold, cryptographic erasure + destruction certificate	Working
Public verifier, citizen portal	Working
Six Solidity contracts on a permissioned EVM chain	Working, 18 tests, deployable

Deliberately simulated, and labelled as such everywhere it appears: DSC signing (Ed25519 stands in for CCA-licensed Class 3 tokens), OCR (the corpus ships transcripts; the pipeline treats them exactly as OCR output, confidence and verification queue included), the embedding model (hashed n-grams with a curated bilingual lexicon, in place of MuRIL/IndicBERT), HSM key custody (a file, not hardware), and the CCTNS/ICJS/eSakshya/DigiLocker integrations (interfaces defined, no live systems).

Deliberately not built: an offline mobile app, handwriting OCR, predictive policing of any kind. See docs/ARCHITECTURE.md for why the last one is a design decision rather than a gap.

Repository layout

server/          Fastify + TypeScript API
  src/core/      hashing · Merkle trees · envelope encryption · Ed25519 · Shamir over GF(2^8)
  src/policy/    ABAC engine and the baseline rule set
  src/ledger/    anchoring: embedded consortium ledger, or a real permissioned EVM chain
  src/services/  documents · custody · audit · certificates · WSD · search · retention
  src/seed/      the fictional corpus
web/             React + TypeScript console, public verifier, citizen portal
contracts/       six Solidity contracts, Hardhat tests, deploy script (standalone package)
docs/            architecture · demo script · legal mapping · threat model · the solution document

Running against a real permissioned chain

The default is an embedded hash-linked consortium ledger with simulated validators, so the demo boots with no setup. To anchor to an actual EVM chain instead:

cd contracts && npm install
npx hardhat node                                    # or point at your QBFT/IBFT network
npx hardhat test                                    # 18 tests
npx hardhat run scripts/deploy.ts --network localhost
cd .. && PRAMANA_LEDGER=evm npm run dev

Anchors then become real transactions with real block numbers, and the public verifier resolves against them. The AuditAnchor contract verifies the same Merkle proofs the server produces - the test suite builds a proof in TypeScript and checks it in Solidity, which is the cross-check that matters.

Honesty notes

• No real case data is used, and none should ever be loaded into a demo. Every person, case number, phone number and address in the corpus is fictional.
• Every statutory citation is marked [VERIFY] until it has been checked against indiacode.nic.in. Section numbers were written from the problem brief, not from the bare Act. Do not put an unverified citation on a slide - see docs/LEGAL_MAPPING.md and the checklist in docs/SOLUTION.md §22.
• AI output is never evidence. Extracted text, entities and classifications live in a separate namespace, are marked machine-generated with a confidence score, and never touch the sealed original.
• The chain stores proof, never content. A guard rejects any anchor payload that looks like personal data, and it is not overridable. Inspect exactly what was written on the Consortium ledger page.

Documentation

Document	What it covers
docs/PROJECT_BRIEF.md	Start here. The problem, the four mechanisms, current status, and the remaining work
docs/ARCHITECTURE.md	How it fits together, and every demo-vs-production gap
docs/DEMO_SCRIPT.md	The five-minute run, with the exact clicks
docs/LEGAL_MAPPING.md	Statutory obligation → feature, with verification status
docs/THREAT_MODEL.md	Who this is designed against, starting with the insider
docs/SOLUTION.md	The full solution document this was built from
CONTRIBUTING.md	Working agreements, and who owns what

Licence

MIT - see LICENSE.