12Zero
Currently in RBI Sandbox consideration

Payments that
never fail.

Online, on weak signal, or with zero connectivity — 12Zero is the only hybrid payment system with true offline P2P.

Cellular Mode
Balance
₹2,840
Synced via USSD
9:41
●●●▶🔋
Online
Total Balance
₹12,450
Offline limit: ₹500 / ₹500
Recent
☕
Canteen — IIT
Today, 9:12 AM
− ₹80
🥐
Sharma Bakery
Yesterday, offline
− ₹120
Offline P2P
Receive ₹200
QR CODE
650M+
Indians, poor connectivity
$0
UPI MDR for merchants
ZERO
true offline competitors
ONLINE MODE ✓ CELLULAR MODE ✓ TRUE OFFLINE P2P ✓ ECDSA SIGNING ✓ ₹500 OFFLINE LIMIT ✓ RBI COMPLIANT ✓ QR · BLE · NFC ✓ ONLINE MODE ✓ CELLULAR MODE ✓ TRUE OFFLINE P2P ✓ ECDSA SIGNING ✓ ₹500 OFFLINE LIMIT ✓ RBI COMPLIANT ✓ QR · BLE · NFC ✓
The Problem

Every UPI transaction
requires internet.

Railway stations, rural kirana stores, campus canteens during peak hours — when the network drops, payments fail. People pull out cash. The digital economy stops.

190M+
Unbanked Indians with zero access to formal payments
5–8%
UPI failure rate on congested networks — a real daily friction
650M+
Indians with poor or no data connectivity
ZERO
Consumer apps that work with zero cell signal today
How It Works

Three modes. One seamless experience.

12Zero auto-detects signal and silently switches between modes every 3 seconds. No user action. No failed transaction.

🌐
Mode 01
Online
Full internet available. Standard REST APIs via NPCI. Instant confirmation just like GPay or PhonePe.
REST · NPCI UPI Rails · JWT Auth
📶
Mode 02
Cellular
Data weak or congested. Uses the cellular signalling layer — similar to USSD — to carry UPI payloads without internet data.
USSD · Cellular Signalling · *99# Rail
🔵
Mode 03 — Core USP
True Offline P2P
Zero signal. Device-to-device via Bluetooth, QR, or NFC. ECDSA cryptographic signing makes every bundle tamper-proof. Syncs on reconnect.
ECDSA · BLE · QR · NFC · SQLite Ledger
Interactive Prototype

All 6 app screens,
investor-ready.

💳 Wallet
↑ Send
📷 Offline QR
📋 History
📡 Network
🪪 Onboarding
9:41
●●●▶🔋
Online
Total Balance
₹12,450
Offline limit: ₹500 / ₹500 available
Recent Transactions
☕
Canteen — IIT Delhi
Today, 9:12 AM · Online
− ₹80
🥐
Sharma Bakery
Yesterday · OFFLINE
− ₹120
🛒
Raj Kirana & General
2 days ago · Cellular
− ₹145
Under the Hood

Built for trust
at the protocol level.

Every offline transaction is cryptographically signed and tamper-proof. The private key never leaves the device.

🔐
ECDSA Signing
Every transaction bundle is signed with the sender's private key stored in Android Keystore / iOS Secure Enclave. Cannot be forged.
Cryptography
💾
Local SQLite Ledger
Double-entry bookkeeping on-device. All amounts stored in paise integers — no floating point errors. ACID compliant.
Data Layer
🔵
BLE P2P Transfer
react-native-ble-plx handles GATT profile communication. Signed bundles transfer device-to-device via Bluetooth Low Energy.
Connectivity
🔄
Sync Engine
PENDING_SYNC queue flushes automatically on reconnect. Server recomputes balance from full ledger and rejects replays via nonce dedup.
Consistency
🛡️
Fraud Prevention
Nonce uniqueness, txn_id deduplication, ±5 min timestamp drift check, ₹500/day offline cap, and device binding prevent all known attack vectors.
Security
📶
Network Engine
Signal detection every 3 seconds. Priority: Internet → USSD/Cellular → BLE Offline. Mode switches silently. Zero user action required.
Intelligence
Build Roadmap

18 weeks to pilot launch.

7 phases from foundation to real users, real money, real feedback on campus.

0
Phase 0
Foundation — UPI + Finance Basics
Setup, architecture, understanding UPI rails, NPCI, what a ledger is.
Wk 1–2
1
Phase 1
Wallet + Local Ledger
SQLite schema, double-entry bookkeeping, paise integer model.
Wk 3–5
2
Phase 2
Transaction Signing (ECDSA)
Cryptography, SHA-256 hashing, Secure Enclave key storage, signature verification.
Wk 6–7
3
Phase 3
Offline via QR Code
Nonces, replay protection, full offline P2P flow — the core USP in action.
Wk 8–10
4–5
Phase 4–5
Sync Engine + Network Detection
Eventual consistency, settlement, USSD integration, auto mode-switching.
Wk 11–13
6
Phase 6
Bluetooth P2P
BLE protocol, GATT profiles, device pairing, NFC integration.
Wk 14–16
7
Phase 7
Campus Pilot Launch 🎓
Real users, real money, real feedback. IIT/college canteens + hostels.
Wk 17–18