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BumpWallet

BumpWallet

Tap to Pay NFC Wallet

Created on 14th March 2026

BumpWallet

BumpWallet

Tap to Pay NFC Wallet

The problem BumpWallet solves

The Problem

Onchain payments are still far more complicated than everyday digital payments.

Today, sending crypto usually requires users to:

  • Copy and paste long wallet addresses
  • Scan QR codes
  • Switch between multiple apps
  • Manually choose chains and tokens
  • Risk sending funds to the wrong address

These steps introduce friction, confusion, and irreversible mistakes, especially for non-crypto users. Paying someone in crypto should be as simple as tapping a card — but today it isn’t.


The Solution

Bump makes onchain payments feel like contactless payments.

Instead of copying addresses or scanning QR codes, users simply tap phones using NFC to send crypto instantly.

Bump combines identity, payments, and merchant checkout into a single mobile app.


What People Can Use It For

🤝 Peer-to-Peer Payments

Send stablecoins to friends, roommates, freelancers, or sellers by simply tapping phones.

Perfect for:

  • Splitting bills
  • Paying someone back instantly
  • Creator or freelancer payments
  • Informal commerce at events or hackathons

🛍️ Merchant Checkout (Phone-Based POS)

Bump includes a merchant mode, turning any phone into a crypto checkout terminal.

Merchants can:

  • Add items to a simple POS cart
  • Generate a payment request
  • Let customers tap to approve and pay
  • Instantly confirm payment
  • Keep a simple transaction history

No hardware terminals or integrations required.


🪪 Human-Readable Payment Identity

Users can claim a

*.bump.eth

ENS identity for payments.

Instead of sending to a long wallet address like:

0xabc123...9f2

Users pay something recognizable like:

alice.bump.eth

This makes payments more trustworthy and reduces mistakes.


📒 Clear Payment History

Bump keeps a readable record of payments and syncs them to a Fileverse-backed ledger, helping users:

  • Track payments and receipts
  • Review past transactions
  • Treat crypto payments like normal financial activity

Why It’s Better

Bump improves crypto payments by making them:

  • Faster — tap-to-pay instead of copy/paste
  • Safer — ENS identities reduce address mistakes
  • More familiar — uses the same “tap to pay” interaction people already understand
  • All-in-one — wallet, identity, payments, POS, and transaction history in a single app

In Short

Bump turns crypto payments into a simple, real-world interaction: tap phones and pay.

Challenges we ran into

Challenges I Ran Into

NFC Tap-to-Pay Between Phones

Implementing tap-to-pay required handling Android NFC at a low level, including reader mode for the payer and Host Card Emulation (HCE) for the merchant.

Solution

I built custom Android native modules and designed a simple NFC protocol with session IDs and structured payment payloads to ensure reliable tap interactions.

Reliable Payment Confirmation

Blockchain events alone can be unreliable due to websocket failures or delayed receipts.

Solution

I implemented multiple confirmation layers:

  • realtime event watchers
  • transaction receipt checks
  • transfer log validation
  • polling fallback

This ensures payments are confirmed even if one mechanism fails.


Preventing Replay Attacks in NFC Payments

A simple NFC transfer could allow replay attacks or unsigned payment requests.

Solution

Payments use EIP-712 signed authorizations verified by an onchain contract with nonce and deadline checks, supporting both EOAs and ERC-1271 smart wallets.

Tracks Applied (5)

DeFi

DeFi Bump fits the DeFi track because it turns decentralized financial infrastructure into a real-world payment experie...Read More

Best creative use of ENS

Ethereum Name Service Bump fits the Ethereum Name Service (ENS) track because ENS is used as a core part of the payment...Read More
Ethereum Name Service

Ethereum Name Service

Best Privacy Application using BitGo

https://github.com/0xgeorgemathew/bumpay/blob/main/bitgo-code-usage.md BitGo Partner Track: Best Privacy Application us...Read More
BitGo

BitGo

DeFi 2.0 - New Primitives

Base Bump integrates with Base infrastructure to power a smooth onchain payment experience. User wallets are implement...Read More
Base

Base

BEST Overall Project

Best Overall Project Bump fits the Best Overall Project track because it turns multiple blockchain components into one ...Read More

Cheer Project

Cheering for a project means supporting a project you like with as little as 0.0025 ETH. Right now, you can Cheer using ETH on Arbitrum, Optimism and Base.

Discussion

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