Extending Blockchain’s Universality
CBDC &
Mobile Payment Apps: the need for Universal Interoperability
using Blockchains
©Prof
Archie D’Souza
A Central Bank Digital
Currency (CBDC) is a digital version of a country’s official fiat
currency, issued and regulated by the central bank rather than private
entities, making it a sovereign digital currency with the same legal status as
physical cash. Unlike cryptocurrencies such as Bitcoin or Ethereum, which are
decentralized and often volatile, CBDCs are centralized and fully backed by the
government, ensuring trust and stability. CBDCs can be used for everyday
transactions, including person-to-person (P2P) and person-to-merchant (P2M)
payments, and may operate alongside physical cash. They are typically stored
in digital wallets provided by banks or authorized
institutions, allowing users to send, receive, and store money securely. For
example, India’s Digital Rupee (e₹) is a CBDC issued by the
Reserve Bank of India, offering features similar to physical currency, such as
legal tender status, instant settlement, and offline transaction capabilities. CBDCs
aim to enhance financial inclusion, improve payment efficiency, and
reduce transaction costs, while also providing central banks with better
tools for monetary policy and financial stability. Countries like the Bahamas,
China, Nigeria, and India have already piloted or implemented CBDCs,
demonstrating their growing global adoption. In summary, CBDC is a
government-backed digital currency that functions as legal tender, offering a
secure, efficient, and modern alternative to traditional cash.
Here are two links that talk at
length on the subject:
https://www.bankopedia.co.in/fintech/india-digital-rupee-cbdc-explained
and
Paytm, which started operations
in 2014, is the oldest mobile payment app in India. No mention of this subject
can be made without acknowledging Paytm’s pioneering role in introducing
prepaid mobile wallets. The Unified Payment Interface, set up by the National
Payments Corporation of India (NPCI) has revolutionised the way businesses and
individuals make and receive payments. I intend making a case of why they
should be integrated into blockchains. The Government of India need to work out
the transition to how NPCI’s UPI transformed the ecosystem into a direct
bank-to-bank interoperable network.
When Paytm launched in 2014, it
set off a digital transformation across India by proving that everyday
transactions could move away from physical cash. However, these early mobile
wallets operated primarily as closed-loop systems—users could only transact
seamlessly within the same app ecosystem. The turning point came with the
National Payments Corporation of India (NPCI) and the introduction of the
Unified Payments Interface (UPI). By decoupling payments from private app
wallets and linking them directly to bank accounts, UPI democratized payment
rails across the nation, creating a unified, highly interoperable ecosystem
that revolutionized daily commerce.
The Domestic Ceiling & The
CBDC Frontier: While UPI solved national interoperability, digital finance
is fast approaching a new threshold. Today’s payment systems remain centralized
and domestically bounded. Crossing international borders still requires
navigating complex correspondent banking networks, incurring high fees, and
enduring settlement delays. Concurrently, central banks globally—including the
Reserve Bank of India—are rolling out Central Bank Digital Currencies (CBDCs).
Yet, if CBDCs and existing instant payment platforms (like UPI and Paytm)
operate in isolated digital silos, they risk recreating the fragmented payment
landscapes of the past.
Why Blockchain Serves as the
Universal Interoperability Engine: This is where blockchain technology
becomes non-negotiable. Blockchains offer a decentralized, immutable, and
globally accessible protocol layer capable of uniting private fintech apps,
national rails, and sovereign CBDCs. Integrating domestic platforms like UPI
and mobile wallets with blockchain infrastructure yields three critical
advantages:
- Seamless Cross-Border Liquidity: By
utilizing blockchain as a neutral settlement ledger, a UPI payment
initiated in India could instantly settle with a merchant or recipient
abroad using another nation’s CBDC or digital asset, eliminating
cross-border friction.
- Programmable Commerce: Leveraging smart
contracts on a blockchain enables automated, conditional payments—such as
escrow settlements, automated supply chain payouts, or
micro-transfers—directly triggered by real-world events without human
intervention or centralized clearinghouses.
- True Platform Agnosticism: Blockchains
remove dependency on proprietary gateways, allowing private wallets
(Paytm), public payment rails (UPI), and central bank tokens (CBDCs) to
interact frictionlessly under a unified, secure standard.
Building the Global Fabric:
Pioneers like Paytm showed how digital payments could start, and UPI
demonstrated how a nation could scale them. The next paradigm shift lies in
scaling interoperability beyond domestic borders. By adopting blockchain as the
underlying connector, we move closer to a financial landscape where money moves
as freely, instantly, and universally as information on the internet.