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) On February 7, 2025, the Reserve Bank of India (RBI) quietly made one of the most technically consequential announcements for India’s financial infrastructure since UPI: an exclusive, regulated namespace for financial institutions and a plan to extend strong authentication to international online card transactions. What reads like a routine regulatory update is, in practice, a fundamental redesign of the trust model for Indian digital banking — moving part of the security story from ad-hoc brand protection to a verifiable, policy-backed slice of the Domain Name System (DNS).

A Regulated Slice of the Internet: Inside ‘bank.in’

RBI Governor Sanjay Malhotra announced that from April 2025, Indian banks will be able to register domains under an exclusive `bank.in` namespace, with `fin.in` to follow for non-bank financial entities. The Institute for Development and Research in Banking Technology (IDRBT) will serve as the exclusive registrar. For years, Indian banks have operated across a patchwork of domains — `.com`, `.co.in`, slightly misspelled variants, brand experiments, and legacy URLs — a landscape that phishers have exploited relentlessly. The RBI’s new move reframes that landscape:

  • bank.in becomes a controlled namespace.
  • Eligibility is tightly scoped to regulated Indian banks.
  • Registration is centralized under a sector-aware registrar (IDRBT), not a generic commercial registrar.

This is not just branding. It’s protocol-level signaling.

Why This Matters to Security Teams and Engineers

For attackers, domain confusion is a feature, not a bug. Homoglyph attacks, lookalike domains, and throwaway hosting have kept phishing ahead of mainstream user awareness. A curated `bank.in` namespace creates a powerful security primitive:

  1. Stronger user mental model

    • When consistently messaged — "only trust *.bank.in for Indian banks" — users get a deterministic trust anchor.
    • This mirrors the intention behind initiatives like .bank globally, but with the advantage of RBI’s regulatory authority and India’s high digital payments penetration.

  2. Machine-verifiable trust

    • Security products, email gateways, and browser extensions can hard-code or dynamically fetch an authoritative list of valid bank.in domains from IDRBT.
    • This enables:
      • Policy-based checks ("allow login links only if domain ends with bank.in and is present in registry")
      • Stronger anti-phishing signals for spam filters, mobile app link handling, and in-app browsers.

  3. Tighter operational controls

    • Centralized registration allows RBI/IDRBT to enforce:
      • Mandatory DNSSEC for bank.in records
      • Minimum TLS standards (modern ciphers, HSTS, certificate pinning policies)
      • Verified hosting and contact metadata
    • This turns the TLD-level policy surface into a security control plane rather than a passive label.
For engineering and security leaders inside banks, this creates both an opportunity and a deadline. Expect RBI and IDRBT to push for:
  • Migration plans from legacy domains to bank.in (or strong cross-linking plus HSTS and canonicalization).
  • Phased deprecation of unaudited lookalike domains.
  • Integration of bank.in verification into mobile apps, SDKs, QR flows, notification templates, and SMS/WhatsApp deep links.

The winners will be teams that treat this not as a compliance checkbox, but as a chance to systematically reduce one of the biggest real-world attack vectors: user confusion.

‘fin.in’: Bringing Fintech Into the Same Trust Fabric

The forthcoming fin.in domain for non-bank financial entities is strategically just as important.

India’s threat surface is no longer just banks:

  • Wallets, neo-banks, NBFCs
  • Lending apps
  • Investment platforms
  • Insurtech and regtech players

Many operate in regulatory gray zones from the user’s perspective, and their domain choices are often indistinguishable from outright scams.

By introducing a gated fin.in namespace:

  • RBI and allied regulators can create a visible, cryptographically anchored signal that an entity sits within a supervised perimeter.
  • Consumers gain a differentiator between a random .com lending site and a regulated entity on fin.in.
  • Developers building aggregators, AA (Account Aggregator) stacks, or payment initiation flows can embed fin.in validation rules directly into their trust frameworks.

However, execution will be everything.

Key open technical and policy questions implementers should watch:

  • Will fin.in eligibility be tightly bound to licensing status? (It should be.)
  • Will RBI publish machine-readable registries (JSON feeds, DNS-based lookups, signed lists) for both bank.in and fin.in?
  • Will there be mandatory DNSSEC, certificate transparency monitoring, and incident reporting tied to these domains?

If implemented rigorously, fin.in could become a canonical hook for:

  • Zero-trust style validations between financial services
  • Safer deep-linking in super apps and wallets
  • Programmatic fraud detection at the network edge

Extending AFA to Global: Stronger Rails for Card-Not-Present

The second prong of RBI’s update targets a softer spot: cross-border, card-not-present (CNP) transactions.

India’s domestic digital payments ecosystem has normalized strong customer authentication (SCA) through Additional Factor of Authentication (AFA) — typically OTP, device binding, or app-based approval. But this rigor stopped at the border. International online transactions using Indian-issued cards often ran with weaker or absent step-up authentication, raising both fraud risk and consumer anxiety.

RBI now proposes enabling AFA for international CNP transactions "where the overseas merchant is enabled for AFA," with a draft circular to follow for stakeholder feedback.

Implementation Implications for Payment Engineers

For issuers, networks, and payment gateways, this is a non-trivial but overdue alignment of global rails with India’s security posture.

You should expect and prepare for:

  • Deeper reliance on protocols like EMV 3-D Secure 2.x

    • Dynamic, risk-based challenges rather than blunt OTP for every transaction.
    • Better device fingerprinting and behavioral analytics.

  • Adaptive AFA flows

    • Merchants and PSPs that support AFA can trigger RBI-compliant flows for Indian cards.
    • Non-supporting merchants may be subject to issuer-driven controls, limits, or step-up requirements.

  • UX and performance engineering challenges

    • Minimizing friction while satisfying AFA will require:
      • Low-latency challenge APIs.
      • Thoughtful mobile-first flows.
      • Graceful handling of failures and timeouts.

  • Liability and dispute recalibration

    • Strong authentication, when done correctly, can reduce chargeback disputes and clarify responsibility boundaries across issuer, network, and merchant.

The subtext: RBI is exporting India’s “high-friction, high-trust” DNA into the cross-border environment — but modernized through risk-based and protocol-native implementations rather than only SMS OTP.

For Developers and CISOs: Action Items, Not Headlines

This policy shift is not a spectator event for the technical community. It is a roadmap.

If you are a bank, fintech, or infrastructure provider, here’s what should already be on your whiteboard:

  1. Domain strategy and migration

    • Reserve your bank.in (or future fin.in) domain as soon as eligible.
    • Implement:
      • HSTS with preload for primary domains.
      • Strict redirect and canonical URL strategies.
      • DNSSEC for all critical records.
    • Start sunsetting confusing or unused legacy domains.

  2. Machine-readable trust integration

    • Push RBI/IDRBT (via industry bodies) to expose signed registries of authorized bank.in/fin.in domains.
    • Integrate these lists into:
      • Fraud engines
      • Email and SMS filtering
      • In-app browsers and link validation logic

  3. User education, but with technical teeth

    • Don’t just release a press note.
    • Update all communications, SDKs, and app flows to consistently reinforce:
      • "We only operate under *.bank.in" (once fully migrated).
    • Use in-app detections to warn users when they’re about to visit lookalike domains from bank-themed messages.

  4. AFA-ready payments architecture

    • Ensure support for EMV 3DS 2.x and dynamic, step-up flows for both domestic and international CNP.
    • Design authentication services (OTP, app-based approval, FIDO2/WebAuthn where feasible) as reusable, low-latency, highly available internal platforms.
    • Work with networks and international merchants to test end-to-end AFA flows early.

  5. Coordinated incident response using the new rails

    • Treat misuse of bank.in/fin.in as a high-severity event with clear public guidance.
    • Combine certificate transparency logs, DNS monitoring, and RBI/IDRBT feeds to detect anomalies fast.

A More Opinionated Internet for Indian Finance

The RBI’s announcement is more than defensive housekeeping. It’s a declaration that India is willing to shape the internet substrate itself — domains, authentication norms, and trust signals — to match the scale and stakes of its digital financial ecosystem.

For a developer, this is a clear brief: the address bar, the DNS record, and the 3DS challenge are no longer peripheral UX details. They are regulated security surfaces that must be engineered deliberately.

For attackers, it narrows the playground.

For everyone building the next decade of Indian fintech infrastructure, it’s an invitation — and a warning — to align with a more opinionated, verifiable, and protocol-driven model of trust, before the phishing kits and fraud rings refactor theirs.

Source: The Hindu (https://www.thehindu.com/business/banks-to-have-bankin-internet-domain-name-non-banks-finin-rbi/article69191225.ece)