rs of iOS devices can now download a decentralized wallet app that connects directly to the bitcoin network, making it different from other server-based products on the market.
Breadwallet is the first bitcoin wallet app of its kind on Apple's platform. Its creator says users are not vulnerable to server downtime or the hacking attacks that sometimes strike centralized providers, and wallet management remains straightforward enough for the average user.
Instead of running through central servers, Breadwallet accesses the bitcoin network directly, using 'simplified payment verification' (SPV). Developer Aaron Voisine said he prefers this to other iOS apps that are "server-trusting" or just "wrappers around web windows", building his own SPV backend from scratch.
Breadwallet is a BIP32 HD or 'hierarchical deterministic' wallet, which means all of a user's bitcoin addresses (public and private) and balances can be recovered with a single unique phrase. Provided you remember the phrase, users' wallets will never need backups and can be restored on other devices even if the original is lost, broken or stolen.
That being so, Breadwallet is staking a claim as iOS's first decentralized bitcoin wallet. The Android version of Hive wallet is built on Mike Hearn's bitcoinj and thus is listed as 'decentralized' by bitcoin.org, but its iOS version is not.
Hive does, however, use a similar deterministic tree structure (BIP39) to Breadwallet, meaning backup phrases from each app may be used on the other.
Choosing a more secure platform
Voisine said he chose iOS because he wanted to create an app that anyone could use relatively safely, without needing to know how to secure a desktop or Android device – something even more technical users often struggle to do properly.
"As bitcoin grows to become a major world currency, malware theft is going to be a huge problem. Stealing digital cash is way more lucrative than turning people's machines into spambots or stealing credit cards."
Apple's tight grip over its native platform was actually the best way to reduce the threat of malware, he added. Further, iOS is the only popular platform that hardware-encrypts the filesystem by default, giving added protection to users who lose physical access to their devices.
However, Voisine said that users of 'jailbroken' iOS devices should not install Breadwallet – or any kind of bitcoin wallet.
"You're going to get robbed because you think you know more than you actually do. Any jailbreak app has total control of your phone and your wallet. I understand the temptation to use it with a little bit of money, but you will get lazy because it will be convenient to use right up until it isn't."
He added that he wanted to make a wallet with a "beautiful, convenient user experience that is also as secure as possible for people who have zero understanding of computer security."
Bitcoin matures on iOS
Bitcoin users with iOS devices have seen a dramatic improvement in wallet options in just the past few months. No sooner had Apple quietly ceased its policy against bitcoin wallet and payment apps in June, than the first examples began to appear.
There are now over 10 wallet and payment options available on iOS, includng Blockchain, Gliph, Hive, Coin Pocket, Bity and GreenAddress.
He said he was convinced Apple would change its policy on bitcoin apps eventually, and set to work months before the decision was made in order to be ready to submit on the first day Apple allowed it.
The long head start turned out to be prudent – the biggest challenge Voisine faced was building the app's SPV mode bitcoin network client portion. No-one had written this for iOS previously, and it took him six months to complete, he said:
"All the Android wallets that are SPV use Mike Hearn's bitcoinj, which took over a year to write."
Breadwallet is free to download and use from the iOS App Store.
Images via Breadwallet