How Ledger’s Implementation Of Miniscript For Bitcoin Opens A World of Possibilities

Ledger devices are the first hardware wallets to implement Miniscript for Bitcoin, highlighting our dedication to adopting new features as soon as they’re available, as we’ve done with Taproot, which we supported on day one. In this article, I explain how Miniscript promises to change Bitcoin transactions, and how we plan to leverage this breakthrough technology to deliver the best experience to our users.

What Bitcoin Miniscript brings to the table

Bitcoin Miniscript is a high-level language for expressing Bitcoin Script designed and implemented by Pieter Wuille, Andrew Poelstra, and Sanket Kanjalkar at Blockstream Research. It has been supported in Bitcoin Core since version 25.0, thanks to the work of Antoine Poinsot from WizardSardine.

Unlike traditional Bitcoin scripts that rely on rigid rules, Miniscript employs a more dynamic and customizable framework. In this regard, Miniscript for Bitcoin represents a significant leap forward, creating tailored spending conditions that are more adapted to specific user needs. 

For instance, Miniscript for Bitcoin enables more sophisticated multisig wallets and greater protection against single points of failure. This is particularly beneficial for scenarios where multiple parties need to authorize transactions, such as corporate treasuries or joint accounts, as Ledger’s CTO Charles Guillemet outlines in this publication. Something else you could do with a Miniscript-enabled wallet is to create wallets where another party is added after a pre-decided time. Imagine a wallet is a 2-of-2 (for example, two company managers); after six months, it could become a 2-of-3 between the same two managers and a lawyer in case of disagreement.

Miniscript for Bitcoin also enables time-locked transactions. An interesting use case concerns the domain of inheritance. Let’s say you last moved your funds six months ago. With a Miniscript-enabled Bitcoin wallet, your heirs could get access to it automatically after this given period. An allocation could be settled for your three kids after a certain period, and after a year, a notary could access the funds in case they disagree or can’t access the funds for any reason.

Time-locked wallet backup is another interesting application. Let’s say you lose your primary key (or keys if it’s a multi-sig). With a Miniscript-enabled wallet, an additional way to spend funds could become available after six months. Miniscript is a way to perform “trustless assisted custody,” too. Imagine your main spending path requires the key of a (semi-trusted) service, but after a predetermined period, you can spend the coins without the service. Today, an interesting application is Liana, a Bitcoin wallet leveraging on-chain timelocks for safety and recovery, allowing you to safely bequeath your assets to your beneficiaries.

Combined, such use cases have the potential to bring more capabilities to the Bitcoin network and open a world of use cases that remain ahead of us. In this regard, our support of Miniscript for Bitcoin could let users do much more with their secure devices.

Concluding Remarks

What we see today with Bitcoin Miniscript is just the tip of the iceberg. As this scripting language continues to gain traction, we expect to see a more comprehensive range of use cases emerge and bring concrete utility to Bitcoin users. At Ledger, we will always remain at the forefront of these evolutions to bring the most advanced and secure services to our growing community of users.