Powered by Ethereum Relayer, Former Aerospace Engineers Take Flight With Privacy Dapp

Fresh out of school armed with an education in aerospace engineering, Ben DiFrancesco headed straight to Boeing and worked for a few years among the best engineers in the field. In 2012, DiFrancesco learned about a new technology called blockchain and cryptocurrency, and fell down the rabbit hole hard. He founded ScopeLift in 2013 as a traditional Web2 and mobile development shop but pivoted his business to crypto clients in 2019.

It was around that time that DiFrancesco met Matt Solomon, another former aerospace engineer at Lockheed Martin who had left the field to focus on crypto. While they were rivals in the aerospace industry, they became teammates in the world of crypto. Solomon became ScopeLift’s first crypto-focused hire, joining in early 2020 as senior blockchain engineer.

“Our mission is to help build a decentralized future,” says DiFrancesco, a lifelong native of Philadelphia. “That means working with awesome clients in the space and helping them achieve their goals.”

He and the ScopeLift team have had the opportunity to work with crypto clients such as Gitcoin, Optimism, Uniswap, Endaoment, Cozy and other protocols in the DeFi ecosystem. Like many Web3 developers, they also contribute to the ecosystem by helping solve current challenges in creative ways.

Umbra: Enabling Private P2P Payments

Umbra, one of ScopeLift’s internal projects, started when DiFrancesco stumbled upon a tweet from Vitalik Buterin describing stealth addresses. DiFrancesco took the idea to Solomon and suggested they build it as a hackathon project at EthGlobal in 2020. Entirely funded by grants, Umbra is a privacy tool that allows users to make non-traceable peer-to-peer payments via a stealth address system.

Unlike bank accounts, blockchain transactions are conducted via publicly visible addresses that can be traced to an individual or entity. Umbra uses elliptic curve cryptography -- one of the fundamental technologies that underpins the Ethereum network -- to make the process of sending and receiving funds on the Ethereum blockchain anonymous, automated and secure.

“If you’ve configured the Umbra app, anyone can generate a brand new address onchain that’s not tied to you, and you would be the only person who can cryptographically generate the private key for that address,” says the ScopeLift CEO.

Sounds like a perfect solution to the privacy dilemma? Not quite.

Infura Transactions Solves UX Challenge

In getting to the minimum viable product, DiFrancesco and Solomon knew they needed to solve a major user experience challenge.

On the Ethereum blockchain, sending transactions incur a gas fee paid in the ETH token. If you are receiving tokens and your address doesn’t have enough ETH to pay for gas fees, you will have to send ETH to that address before the transaction can be processed successfully.

Therein lies the challenge. If you use an existing address, you are giving up your privacy and it would be obvious who the recipient was. That defeats the purpose of a privacy dapp designed to offer stealth P2P payments.

As a user of Infura’s Ethereum API, DiFrancesco discovered the perfect solution in Infura Transactions (ITX). Via ITX, an Ethereum transaction relaying service, Umbra now allows users to receive, withdraw and move tokens with a transaction fee deduction of the native token.

“We are using all of Infura’s infrastructure under the hood to enable that in an efficient and easy way,” says the former aerospace engineer. “For the user, it feels like a normal send/receive/withdraw experience. ITX provides that ‘gasless’ token experience and privacy-preserving convenience for our users.”

Production Ready: Set Your Gas Tank and Forget About It

The team considered building their own relayer and other solutions, and went with ITX instead. In particular, they were impressed with the dynamic gas price escalation algorithm and real-time fee adjustments. ITX periodically republishes transactions with competitive gas prices to ensure transactions are always picked up by the network.

“What ITX was capable of was way more robust than what we would have built ourselves,” DiFranceso says. “Gas estimation is a very hard challenge. We receive payments in the specific token but pay for gas in ETH. With volatility, it’s really important to minimize the ETH fees we are paying and to be confident that transactions are mined at a reasonable gas price, without getting stuck, but also without overpaying. That affects our bottomline.”

ITX offered a robust and tested solution, and managed all the edge cases -- all through an addon service to the Infura Ethereum API.

In addition to being a superior product, ITX saved the ScopeLift team a few weeks of work if they had built their own relaying system and the headache of having to maintain the infrastructure tool and monitor for changes in the network and conditions.

Seamless Transaction Management Post EIP-1559

“With EIP-1559, theoretically, it’s gotten easier,” the engineer says. “A lot of things seem easier in theory, but once you do it, there’s a hundred things to think about. If we had built our own relayer system, we would have to think about whether EIP-1559 going live would break our relayer or if we needed to tweak the system by the deadline for the network change.”

EIP-1559, part of the Ethereum London Fork upgrades on Aug. 4, 2021, is a fundamental change to how gas fees are estimated for a transaction on the network. Prior to the Fork, all pending transactions on the network transaction pool would go through a bidding process in order to be picked up by a miner -- sometimes racking up sky-high ETH charges. With EIP-1559, a transaction only needs to pay a clearing price alongside a small tip to entice block producers to include it.

Even with the London fork, EIP-1559 does alleviate the issue around picking a reasonable gas price most of the time. ITX also helps solve other issues by handling transactions that may unforeseeably become “stuck” and offering dedicated infrastructure for sending transactions without a need to tweak the relayer software.

Focus on Building a Great Product

Just last week, the ScopeLift team shipped a major update to the product, one which simplifies setup for new users, and makes sending funds via Umbra easier as well. With this upgrade, the ScopeLift team has taken Umbra out of beta. With ITX to manage user transactions under the hood, the team was able to focus on doing what they do best -- building a differentiated privacy dapp and improving design for product-market fit.

“Outside of ITX, Infura is a key piece of infrastructure of Umbra and all of the projects we work on. It’s a huge piece of the Web3 ecosystem we rely on and appreciate a lot.”

Have an interesting idea for a crypto project? Get started on Infura for free.