Silent Bell

The Trap
Contract card
Trust boundry solution
Student Silent ring
Public Explorer
Failwail duplicate
Failwell Outsider
Live Cast
Commity Inbox
Sign in
Enroll
The solution
Named Emergency
Docker Setup

Inspiration

I still remember the night the corridor lights went out.

I was a first-year. Hostels smell like detergent and wet shoes after eleven. Someone laughed too loud. Someone else whispered that it was just “intro,” just a joke, just something juniors endure if they want to belong. My hands were cold on my phone. I opened the college grievance page twice and closed it twice.

There were only two doors, and both felt like traps.

If I put my name on the complaint, I could see the next three years already-seniors who knew, a warden who “handled it quietly,” the soft punishment of being left out of groups that decide who eats where. My stomach hurt. I was angry, and I was ashamed of being afraid, and I hated that the shame felt louder than the anger.

If I used the anonymous form, I could type everything. But I also knew what the seniors said about those forms: anyone can fill them. Outsiders. Rivalries. Hoaxes. The committee gets a pile of noise and learns to trust nothing. I pictured my words landing in that pile and disappearing. That felt worse than silence-like shouting into a well and hearing only my own echo.

So I did what too many of us do. I locked my phone. I stared at the dark ceiling. I told myself it wasn’t “serious enough.” I slept badly. In the morning I smiled in class like nothing had happened.

I am not submitting that night as a real case. It is a composite story-synthetic on purpose-because real harm should not be content. But the feeling is the product requirement I refused to forget: I needed someone to believe I belonged on this campus without forcing me to hand them my name.

When I found Brainwave’s Midnight Track, I finally had language for that need. Midnight is built for selective disclosure-prove a fact without publishing the private data behind it. So I asked one question, and I built Silent Bell around the answer:

How do I prove I am on this semester’s roll-without revealing which student I am-and without letting outsiders flood the inbox until no one listens?

What it does

I built Silent Bell as a campus pilot product, not a circuit toy.

Trust boundary

When I sign in as the registrar, I publish the semester roster as hashed leaves. Names stay in the CSV. Only membership reaches Compact.

When I sign in as a student, I can ring silently: Midnight learns that someone enrolled filed; it never learns it was me. My story is sealed to the committee key and stored off-chain. Or-if I am in danger and I choose it-I take the named emergency rail and disclose a handle on purpose.

When I sign in as an outsider, the filing fails. That is not a bug. That is the night I was afraid of, solved in reverse: fakes do not get a free microphone.

When I sign in as the committee, I unlock, decrypt on my device, acknowledge, escalate, close, or export. I read the case. On the silent rail, I still do not learn which leaf rang.

The public explorer shows counts and epoch-accountability without voyeurism.

Incident plaintext never hits the ledger. It is sealed with X25519 + AES-GCM to the committee key and stored off-chain.

How we built it

I shaped the product around that fresher’s two bad doors, then wired Midnight underneath.

Architecture

Compact on Midnight Preview (live): contract 5c5312147f35c25ff0ba3aa9771e46e6b19ea1522b232a08b3dacabc95fc4048, deployed 2026-08-26, verified via the Preview indexer. Explorer: explorer.preview.midnight.network. Deployer: mn_addr_preview1guclk6ltr8prs87mu7um563r46fzdtvnazg0vzc8xame8qqhe93s7v7dx6.
Compact circuits-enrol, setEpoch, fileSilent, fileNamed-with a Merkle roster and nullifiers so the same student cannot hoax-flood one category in one semester.
Midnight.js, local proof-server, node, and indexer so the proofs are real, not mocked. The judge live cast runs on the local stack; the Preview address is the public eligibility deploy.
A blob API for sealed capsules and case export, because the story must never be a ledger field.
A role-based UI with FailWell states-outsider rejected, duplicate blocked-so the emotion of “they won’t believe me” has an opposite on screen: the system believed membership, not gossip.

git clone https://github.com/HawaleShailesh004/silentbell.git
cd silentbell
npm install && npm --prefix web install
docker compose up -d --wait
npm run blob && npm run chain && npm run web

Pilot accounts live in COMPAT.md. Rotate them before any real campus.

Challenges we ran into

I wanted the demo to feel like relief, not like debugging theatre-and Midnight’s stack fought me for it.

Public-network wallet sync was the hardest fight: PreProd DUST checkpoints corrupted, Preview indexer threw Wallet.Sync retries for hours. I added print-address so funding does not wait on full sync, then landed the Preview deploy once the wallet finally synced and DUST arrived.
Nested onchain-runtime-v3 copies broke state in ways that looked like “my story vanished”; dedupe fixed it.
A full roster (sixteen leaves) threw exceeded structure bounds mid-cast-the exact nightmare of a system that stops working when you need it. I taught the live cast to reuse existing leaves when the tree is full.
Windows Compact compile forced a Docker path so I could ship instead of stall.

Each of those felt small next to the original fear. Shipping past them still mattered-because a product that fails when a student finally finds courage is another kind of silence.

Accomplishments that we're proud of

I am proud that Silent Bell shows the whole corridor, not one happy screen: registrar, student, outsider fail, duplicate fail, named emergency, committee unlock, public counts.

I am proud of the one-click live cast-judges watch membership proven and identity withheld in one breath on real Compact proofs.

I am proud the Compact circuit is on Midnight Preview for track eligibility-not only on a laptop Docker net.

I am proud we kept the trust boundary honest in the UI: what stays on the device, what Midnight may learn, what the committee never sees on the silent rail.

And I am proud we label the narrative synthetic. The emotion is the brief. Real people deserve process, counsel, and keys we have not finished yet.

What we learned

I learned that privacy tech only matters when someone is already shivering with a phone in their hands.

I learned Midnight is not “ZK for fun.” It is for the moment you need a campus to trust enrolment without demanding identity.

I learned institutional products need roles, empty states, export, and recovery-because courage is rare, and systems must not waste it.

What's next for Silent Bell

Next, I want the fresher in that dark corridor to open a button inside the portal she already uses-not a crypto app she has never heard of.

Campus SSO instead of pilot passwords
SIS roster ingest instead of demo CSV seeds
Committee keys in a real ceremony, rotated each semester
One college MoU for a synthetic pilot under counsel
Later: the same membership pattern for employment whistleblowing and benefits eligibility-prove you belong, without putting your name on the fire

Silent Bell is my answer to that night I locked my phone. Prove you are on the roll. Never force the name. Never let fakes own the microphone.