The open-source nature of hardware cryptocurrency wallets allows individuals with the necessary skills to build their own do-it-yourself (DIY) wallets. Florin Cocos, an electronics design manager from Romania, successfully created his own DIY Trezor in 2018 using the wallet’s open-source code. Despite not having access to an official Trezor device, Cocos documented the entire process on his YouTube channel, Voltlog. He demonstrated how he built the DIY Trezor Model One by purchasing electronics components from distributors such as Farnell and assembling them with a microcontroller and printed circuit board (PCB) sourced from China.
Cocos emphasized that anyone with the skills can purchase the required parts from reputable distributors and obtain the OLED screen from platforms like AliExpress or eBay. The engineer, who still actively uses his DIY device, stated that he trusts it more than a marketplace-bought one. His main motivation for building the DIY Trezor was to promote open-source projects, as he believes they are the future.
The entire process of building and installing firmware on the DIY Trezor took approximately 10 hours for Cocos, excluding the time spent waiting for the PCBs and other ordered components to arrive. Evaluating the project, generating the necessary Gerber files, and ordering the required parts from distributors took a couple of hours. Once the PCBs arrived, it took Cocos around five hours to assemble them, flash the firmware, and get the DIY Trezor up and running.
While building the hardware was relatively straightforward, Cocos admitted that flashing the firmware and making it compatible with the application posed slightly more of a challenge. He emphasized that despite the seemingly short duration for the entire building process, constructing a DIY Trezor is not an easy task for the average user. Cocos rated the difficulty level as nearly impossible without any electronics knowledge.
Cocos suggested that simplifying the process could introduce significant security risks related to supply chain and manufacturing vulnerabilities. He mentioned the potential for creating a “makers pack” that includes all the necessary manufacturing files, which users could upload to PCB and PCBA prototyping services. However, this convenience comes at the expense of relinquishing control over the supply chain, thereby increasing security risks.
The engineer strongly advised against inexperienced individuals attempting to build a hardware wallet without proper knowledge, as it could lead to security breaches or render the device useless. While he acknowledged that one does not need to be as experienced as himself, Cocos believed that one or two years of tinkering with electronics should significantly enhance the chances of success.
In the past, some cryptocurrency users fell victim to fake hardware wallets when purchasing from unauthorized sources. To combat this issue, hardware wallet manufacturers like Trezor have stressed the importance of buying only from official vendors. However, in regions where hardware wallets cannot be shipped due to various reasons, the open-source nature of devices like Trezor provides an alternative solution. Trezor’s Bitcoin analyst, Josef Tetek, stated that anyone can build their own Trezor using the schematics and bill of materials available on GitHub.
Overall, the DIY Trezor project undertaken by Florin Cocos highlights both the potential and challenges of building a hardware cryptocurrency wallet from scratch. While it is accessible to those with the necessary skills and knowledge, it is not recommended for inexperienced users due to the complexity and associated security risks.