3.3 Wallets, Mobile P2P, Digital Cash & Virtual Currencies

Smartphone / Mobile Wallets

A digital wallet is a software application that stores payment instruments (cards, bank accounts, balance) and enables payments via mobile.

Types of wallets

RBI classifies digital wallets into four operational categories. A closed wallet can be used only inside one merchant's ecosystem — Amazon Pay balance to buy on Amazon, Ola Money's legacy balance for Ola rides. Closed wallets are essentially store credit; they don't require a payments licence. A semi-closed wallet can be used across multiple participating merchants but does not allow cash withdrawal — Paytm in its early years, MobiKwik, FreeCharge. Semi-closed wallets need a Prepaid Payment Instrument (PPI) licence from RBI. An open wallet is issued by a bank and allows cash withdrawal at ATMs, peer-to-peer transfers, and full bank-like usage — most modern wallets have effectively become open or have been replaced by UPI. A pass-through (tokenised) wallet like Apple Pay or Google Pay in card mode does not hold a balance itself — it stores a tokenised reference to the user's card and routes the transaction through the card network at payment time.

Indian wallet landscape

Wallet KYC tiers (RBI)

RBI requires every wallet to operate under one of two KYC tiers. A minimum-KYC wallet (also called "small wallet") can be opened with just a mobile number and OTP and allows up to ₹10,000 of loading per month. A full-KYC wallet — opened by submitting PAN, photo, address proof, and linking a bank account — raises the monthly load limit to ₹2 lakh and enables wallet-to-bank-account transfers. The two-tier structure is RBI's way of letting first-time users onboard frictionlessly while still applying anti-money-laundering controls at higher transaction volumes.

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Social / Mobile P2P Payments

Peer-to-peer (P2P) payment = send money to another individual via mobile, without bank visit.

Global P2P apps

Why P2P payments matter

• Splitting bills at restaurants, trips, rent
• Personal transfers to family, friends
• Domestic remittance (city-to-village)
• Tipping delivery, service staff
• Small-merchant payments (street vendors, kirana)

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Digital Cash

Digital cash is an attempt to create the electronic equivalent of physical cash — anonymous, untraceable, transferable peer-to-peer, no intermediary required.

Properties of an ideal digital cash

History of digital cash

Digital cash has had a 35-year journey from research curiosity to working trillion-dollar networks. DigiCash, launched in 1989 by cryptographer David Chaum, was the first serious attempt — it used blind signatures to create truly anonymous digital tokens, and was technically brilliant, but the company failed in 1998 because it was ten years ahead of the network and merchant adoption needed to make it useful. NetCash (1993) was a similar academic project from researchers in the US, never moving beyond experimental status. Bitcoin, launched in 2008 by the pseudonymous Satoshi Nakamoto, solved the long-standing double-spend problem without any central authority, using a proof-of-work blockchain — and became the first commercially successful digital cash; its network is now worth over a trillion dollars at most points in the cycle. Ethereum, launched in 2015 by Vitalik Buterin, generalised the model from "digital money" to "programmable money" — smart contracts that execute conditional logic on-chain, enabling DeFi, NFTs, and DAOs.

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Virtual Currencies / Cryptocurrencies

Virtual currency is a digital currency not issued by a government or central bank. Cryptocurrency is virtual currency secured by cryptography.

Bitcoin — the original cryptocurrency

Other major cryptocurrencies

Crypto payment in e-commerce

• Tesla briefly accepted Bitcoin (paused 2021)
• Microsoft, Newegg, Overstock accept crypto in US
• Whitelabel processors like BitPay, Coinbase Commerce
• In India: limited; most platforms don't accept due to regulatory ambiguity

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CBDC — Central Bank Digital Currency

A CBDC is a digital currency issued by a central bank — combining digital convenience with sovereign backing.

Indian CBDC — Digital Rupee (e₹)

CBDC vs Cryptocurrency

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Digital Token-Based Payment Systems

Definition: payment via cryptographic tokens that represent value. Categories:

1. e-Cash (Chaum's DigiCash)

• Bank issues digital tokens (signed coins)
• User can spend tokens at merchants
• Merchant deposits with bank
• Anonymous (cryptographic blind signatures)
• Failed commercially — ahead of its time

2. e-Cheque

• Digital equivalent of paper cheque
• Signed by payer's digital signature
• Routed through banking system
• Used in B2B (legal validity in India under IT Act 2000)

3. Stored-value tokens

• Loaded amount stored as tokens on card/app
• Examples: Delhi Metro card, fastag (highway toll)

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Comparison — payment mechanism types

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Key Terms — Lesson 3.3

This lesson covers four distinct payment instruments — wallets, P2P apps, digital cash, virtual currencies / CBDC. The vocabulary below is the working glossary across all four.

Digital Wallet (E-Wallet) — A software application — usually on a smartphone — that stores payment instruments (cards, bank accounts, wallet balance) and lets the user pay merchants or other individuals from a single interface. Modern wallets in India have largely been replaced by UPI apps; closed wallets (Amazon Pay, Tata Neu Pay) still survive for in-ecosystem cashback and gift-card use cases.

Closed Wallet — A wallet that can be used only within a single merchant's ecosystem — Amazon Pay balance for Amazon purchases, Tata Neu balance for Tata brands. Closed wallets are essentially store credit; they don't need a payments licence.

Semi-Closed Wallet — A wallet usable at multiple participating merchants but with no cash withdrawal. Requires an RBI Prepaid Payment Instrument (PPI) licence. Paytm in its early years, MobiKwik, FreeCharge are the classic examples.

Open Wallet — A wallet issued by a bank that allows cash withdrawal at ATMs and full bank-like use. Most have effectively merged into mobile banking.

Pass-Through Wallet — A wallet (Apple Pay, Google Pay in card mode) that does not hold a balance but stores a tokenised reference to the underlying card; transactions route through the card network at payment time.

Prepaid Payment Instrument (PPI) — RBI's umbrella term for any non-bank instrument loaded with value in advance and usable for payments — wallets, prepaid cards, gift cards, meal vouchers. PPI issuers need an RBI licence and must follow KYC norms.

KYC (Know Your Customer) — The regulatory requirement that any financial institution verify the identity of its customers — for wallets, banks, mutual funds, crypto exchanges. India's standard KYC uses Aadhaar + PAN (with optional video KYC) for full KYC; mobile + OTP alone qualifies for minimum-KYC limits.

P2P (Peer-to-Peer) Payment — A payment from one individual directly to another, typically via mobile app, without visiting a bank. UPI, PayPal, Venmo, Cash App, Zelle, M-Pesa, PIX, Alipay, WeChat Pay are the major P2P networks worldwide. P2P drives bill-splitting, family transfers, tipping, and small-merchant payments.

M-Pesa — Kenya's pioneering mobile-money system launched by Safaricom in 2007. M-Pesa lets users send/receive money using their SIM, even on feature phones, and has been credited with raising 2% of Kenyan households out of poverty. It is the template most African and South Asian mobile-money systems followed.

PIX (Brazil) — Brazil's real-time, 24×7, free retail payment system launched by the central bank in 2020. PIX is the closest international analogue to UPI in design and impact — both are central-bank-driven, free for users, and have rapidly displaced cards in domestic retail.

Digital Cash / E-Cash — A long-standing research goal: an electronic equivalent of physical cash — anonymous, transferable peer-to-peer, divisible, off-line capable, non-forgeable, and protected against double-spending. The seven properties form the IPU textbook's framework for evaluating any candidate digital-cash system.

Double-Spend Problem — The technical challenge unique to digital cash: a digital token is just a copy-able number, so what stops the holder from spending the same token at two different merchants? Pre-blockchain solutions relied on a trusted central authority (bank). Bitcoin's innovation was solving double-spend without any central authority, using a proof-of-work blockchain.

Blockchain — A distributed, append-only ledger where transactions are grouped into blocks, each cryptographically linked to the previous one, and a network of nodes agrees on the chain through a consensus mechanism (proof-of-work, proof-of-stake, etc.). Blockchains make double-spend prevention trustless — you don't need a bank to verify uniqueness.

Cryptocurrency — A digital currency secured by cryptography and operated on a (usually decentralised) blockchain. Bitcoin (2009) was the first; Ethereum (2015) generalised the model. Cryptocurrencies are not legal tender in India but are legal to hold; gains are taxed at 30% plus a 1% TDS on every transaction.

Bitcoin (BTC) — The first successful digital cash, launched 2009 by pseudonymous Satoshi Nakamoto. Total supply is algorithmically capped at 21 million BTC; new blocks are mined ~every 10 minutes; consensus is Proof-of-Work. Bitcoin is treated commercially as "digital gold" — primarily a store of value rather than a daily payment instrument.

Ethereum (ETH) — A "world computer" blockchain launched 2015 by Vitalik Buterin that supports smart contracts — programmable on-chain logic. Ethereum is the platform on which most decentralised finance (DeFi), NFTs, and DAOs are built. Switched from Proof-of-Work to Proof-of-Stake in 2022 (the "Merge"), drastically cutting energy usage.

Stablecoin — A cryptocurrency designed to track the price of a fiat currency or other stable asset, usually 1:1 with the US dollar. USDT (Tether) and USDC (Circle) are the dominant fiat-backed stablecoins; DAI is a leading crypto-collateralised stablecoin. Stablecoins are the de-facto cash equivalent inside crypto markets and a growing rail for cross-border remittance.

Smart Contract — Self-executing code deployed on a blockchain that runs automatically when predefined conditions are met — "if buyer pays X amount, release goods to buyer." Smart contracts power lending protocols (Aave, Compound), exchanges (Uniswap), NFT marketplaces (OpenSea), and a growing variety of programmable-money use cases.

Proof-of-Work (PoW) — The original blockchain consensus mechanism (used by Bitcoin and historically Ethereum). Miners compete to solve a computational puzzle; the first to solve it adds the next block and earns the block reward. PoW is secure but energy-intensive — Bitcoin's annual electricity use rivals that of small countries.

Proof-of-Stake (PoS) — A more energy-efficient consensus mechanism where validators are chosen to propose blocks based on the amount of cryptocurrency they have staked as collateral. Misbehaviour costs the validator their stake. Ethereum migrated to PoS in 2022 and cut its energy use by ~99.95%.

CBDC (Central Bank Digital Currency) — A digital currency issued and backed by a central bank — combining digital convenience with sovereign trust. India's CBDC, the Digital Rupee (e₹), was launched by RBI in pilot in December 2022. Two variants: e₹-W (wholesale, between banks) and e₹-R (retail, for citizens). 130+ countries are at various stages of CBDC research or pilot.

e₹ (Digital Rupee) — RBI's retail and wholesale CBDC. e₹-R is token-based, held in a wallet, and represents a direct claim on the central bank (unlike UPI, where the underlying funds are bank deposits). e₹ is positioned as a complement to UPI rather than a replacement.

e-Cheque — A digital equivalent of a paper cheque — signed by the payer's digital signature, routed through the banking system, legally valid in India under the IT Act 2000 and the Negotiable Instruments (Amendment) Act 2002. Used in B2B for payments that need cheque-style legal evidence without the paper.

Stored-Value Token — A token that holds a pre-loaded balance and decreases as spent — Delhi Metro smart card, FASTag on national highways, fleet petrol cards. Stored-value tokens prioritise speed (no online auth at point of use) and offline operation.

FASTag — India's RFID-based electronic toll-collection sticker on a vehicle's windscreen, debiting toll fees from a linked wallet or bank account as the vehicle passes through a toll plaza. FASTag has been mandatory for all four-wheelers on national highways since 2021 and has effectively eliminated cash toll lanes.

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Study deep

1. The wallet vs UPI debate ended in India. Paytm, PhonePe, Google Pay all pivoted from wallet-first to UPI-first because UPI's network effects (every bank, every account) crushed proprietary wallets. Closed wallets remain useful for cashbacks and gift-card scenarios.

1. Cryptocurrency adoption is uneven. El Salvador made Bitcoin legal tender (2021). India taxes crypto at 30% (2022). China banned it. Different countries reach very different stances based on regulatory philosophy.

1. Stablecoins are the bridge. USDT and USDC enable crypto-rails to deliver fiat-like stability. Cross-border remittance via stablecoins is growing rapidly. RBI is cautious — sees stablecoins as competing with rupee sovereignty.

1. CBDCs are coming globally. 130+ countries are researching or piloting CBDCs (Atlantic Council CBDC Tracker, 2024). China's digital yuan, EU's digital euro, India's e₹ are at advanced stages.

1. Tokenisation is reshaping payments architecture. From card tokenisation (Visa Token Service, RBI's CoF) to UPI tokenisation, the trend is to replace static credentials with dynamic tokens — better security, better privacy.

PYQ pattern: "What are digital wallets? Differentiate closed, semi-closed and open wallets with examples." — Define, table the 3 types with examples (Amazon Pay closed, Paytm semi-closed, bank wallets open).

PYQ pattern: "What is digital cash? Discuss its properties." — Define as electronic equivalent of cash; 7 properties (anonymous, transferable, divisible, off-line, universal, non-forgeable, double-spend-protected); mention Bitcoin as first successful implementation.