Onto banking system and checking frauds before they happen, RBI is mulling using erupee to avoid frauds from taking place.. how do you think erupee cbdc can coexist with ordinary rupees in ordinary bank accounts.. won't it require rampant banking changes in software?
This is a genuinely fascinating systems question — part monetary design, part software architecture. Let me break it down properly.
The Core Idea: Why eRupee for Fraud Prevention?
The key insight RBI is working with is programmability and traceability. Every eRupee transaction is traceable, meaning less fraud and fewer missed subsidies. Programmable payments can ensure money is spent only for intended purposes — school fees, healthcare, groceries.
This is fundamentally different from ordinary rupees in bank accounts. A regular NEFT/IMPS transfer is settled but not governed — once money moves, it's gone and free. eRupee can carry conditions with it.
Programmable CBDC (PCBDC) is a rule-based version of the Digital Rupee that allows money to be "programmed" so it can be used only for specific purposes, in specific locations, or within a defined time period.
Coexistence Architecture: How It Actually Works
This is the crux of your question — and the answer is two-layer monetary system, not a replacement.
Layer 1 — Commercial Bank Money (existing) Your savings/current account balance. Credit-created money, governed by fractional reserve banking. Flows via NEFT/RTGS/UPI.
Layer 2 — CBDC (eRupee) Direct liability of RBI, not the commercial bank. Flows via a separate wallet infrastructure. It is fully interchangeable with existing currency at par (1:1), combining the trust of physical currency with the efficiency of digital payments.
The conversion gateway between Layer 1 and Layer 2 is where banks sit — you debit your savings account, and an equivalent eRupee is issued to your wallet by the bank acting as a distribution intermediary.
The Banking Software Question — Yes, It's Massive
You're absolutely right to flag this. The software changes are non-trivial on multiple dimensions:
1. Core Banking System (CBS) Changes Banks run on ancient CBS platforms (Finacle, BaNCS, Flexcube). They were built around the concept of accounts — a balance held by the bank. CBDC flips this: the balance is held by RBI, and the bank is just a pipe. This means:
- New wallet ledger subsystem separate from account ledger
- Real-time gross settlement hooks at the individual transaction level
- Changes to reconciliation, end-of-day balancing, and liquidity management
2. Interoperability Layer Integration with UPI and fintech platforms is how CBDC can modernize India's payments ecosystem. But UPI today rides on bank account rails. Plugging eRupee wallets into UPI required building a new NPCI-level protocol bridge — which is ongoing.
3. Programmability Engine This is the hardest part. Programmable use cases like subsidies, travel allowances, and geo-locked payments require a smart contract-like rules engine embedded in the transaction processing stack. Each eRupee token (or token batch) needs to carry metadata — expiry, permitted merchant categories, geography — and every payment terminal/gateway needs to validate these rules at the moment of spend.
4. Offline CBDC — A Completely Different Beast A solution from Bank of Baroda's Innovation Centre proposed leveraging existing ATMs and POS machines to help citizens without smartphones use digital currency offline. This means secure local validation without internet — essentially embedding cryptographic state machines in hardware, which is a whole new firmware/HSM problem.
The Systemic Risk RBI Has to Manage
If people move money from bank accounts to CBDC wallets, it could affect bank liquidity and loans. This is called disintermediation risk — if everyone holds eRupee directly, commercial banks lose the deposit base they use for lending. The entire credit creation mechanism of the economy could compress. RBI is likely to impose wallet limits for exactly this reason.
Where It Stands Right Now
The value of eRupee in circulation jumped to ₹1,016 crore at end of March 2025, up from ₹234 crore a year earlier. Still tiny. And RBI's agenda for 2025-26 includes exploring CBDC pilots on cross-border payments on both bilateral and multilateral bases, targeting remittance efficiency given India being the world's largest recipient of remittances.
The fraud-prevention and cross-border angle is where eRupee makes its strongest case — because programmable, traceable money is genuinely harder to launder or misdirect than conventional transfers.
TL;DR for the Software Question
Yes — rampant banking changes. But the design philosophy is deliberately additive rather than replacement:
- Existing CBS stays; a new CBDC ledger layer is bolted alongside it
- UPI gets a wallet interop bridge
- A programmability/rules engine is a greenfield build
- Offline CBDC needs hardware-level cryptographic solutions
The real engineering challenge isn't the happy-path flow — it's reconciliation, fallbacks, and the edge cases when eRupee rules conflict with merchant systems or network failures. India's payment stack (NPCI, UPI) has shown it can move fast on this, but CBDC is structurally more complex than UPI ever was.
