Update Ledger and Trezor firmware and integration libraries with new relevant Cardano features or breaking changes. Update also if there are any breaking changes in Ledger and Trezor core firmware code, testing suites, etc.

Update cardano-hw-cli to reflect firmware changes and to reflect user needs

Support Keystone developers while doing the changes above

Provide general cardano hw wallets maintenance, development support and bugfixing.

Order and manage external code audits for Ledger firmware code (Ledger requirement, has to be done by one of 2 certified auditors)

Hardware wallets Ledger and Trezor and additional supporting tooling (cardano-hw-cli) need to be regularly updated in order to be able to support Cardano blockchain development.

There are 2 aspects of this:

• regular maintenance, bugfixing and developer support
• implementation of new Cardano features and breaking changes

HW wallets in scope: Ledger, Trezor, Keystone (from support perspective as Keystone firmware and tooling is developed by the Keystone team)

Currently it is not known which features in Cardano Roadmap will affect hardware wallets integrations.

If implementation of new Cardano features and breaking changes is not completed then hardware wallets may become incompatible with Cardano, stopping users from accessing newer blockchain features or stop working altogether.

If regular maintenance, bugfixing and developer support is not completed, wallets may lack functionalities and development of tooling that is using HW wallets may become impossible or much more difficult.

New feature implementation should be defined ad-hoc based on Cardano Roadmap projects completion. The maintenance part of this project should be executed continuously and the result should be working HW wallets integration and good developer experience for 3rd party developers.

These are suggested caps for the development. Only work that is actually needed and delivered will be charged (time & material). The contract should be valid for 1 year.

New features implementation - 0.6 FTE - 144 work-days - 187,200 USD Maintenance & support - 0.2 FTE - 48 work-days - 62,400 USD External audits - 35,000 USD

New features implementation part - unknown but from past experience we suggest to allocate 0.6 FTE budget Maintenance & support part - from past experience we suggest to allocate 0.2 FTE budget Duration - 1 year (with regular 1 year extensions at the end of the term) External audits - depending on the size and number of new features implementation

Vacuumlabs has been developing the Cardano HW wallets integrations (Ledger and Trezor) since 2018.

This should be ongoing activity. Cardano HW wallets development consisted of around ~20 small projects through years 2018-2025

The critical maintenance, bugfixing and developer support is currently done by Vacuumlabs for free but this cant last too long. https://github.com/vacuumlabs/cardano-hw-cli/pull/190 https://github.com/vacuumlabs/cardano-hw-cli/pull/188 https://github.com/vacuumlabs/cardano-hw-cli/releases/tag/v1.18.0-rc.1 https://github.com/vacuumlabs/cardano-hw-cli/releases/tag/v1.18.1

We also covered support for developers mainly (mainly SPO tools, various email requests and requests on Cardano Wallets telegram channel)

We will be implementing only features that affect HW wallets and that were delivered to Cardano blockchain through Cardano Roadmap.