[Wallets](https://revain.org/wallets/) › Bitkey

# Bitkey: keys, security, fees and reviews

## In short

- **Account model**: 2-of-3 multisig: a hardware key, an app key on the phone and a server key held by Bitkey; any two keys approve a transaction.
- **Fees**: Device price: USD 250 for the Bitkey kit on the US site (as of 31 October 2026).
- **Risks and caveats**: Only the user controls access to the keys; theft of the phone or hardware combined with recovery tools can be used to steal funds, according to the terms.
- **Checked**: 31 October 2026

## Key facts

- **Official site**: [bitkey.world](https://bitkey.world/)

Key facts checked on 31 October 2026 against official sources.

## What is Bitkey

Bitkey is a Bitcoin-only self-custody wallet made by Block, Inc. (the company behind Square and Cash App). It combines a mobile app, a fingerprint-unlocked hardware device and a Block-run recovery server in a 2-of-3 multisig wallet with no seed phrase; it started shipping on 13 March 2024.

## Who holds the keys

| Parameter | Details |
|---|---|
| Account model | 2-of-3 multisig: a hardware key, an app key on the phone and a server key held by Bitkey; any two keys approve a transaction. |
| Key control | Self-custodial: the user holds two of three keys; Block's single server key cannot move funds on its own. |
| Seed phrase | No seed phrase; the app key is backed up encrypted to the user's personal cloud account. |
| Recovery | Lost phone or device can be recovered with the other two keys; Recovery Contacts help if both are lost. |
| Emergency exit | An Emergency Exit Kit (encrypted app key in PDF form) lets users move funds without Bitkey servers or the app. |

## Features and supported networks

| Parameter | Details |
|---|---|
| Supported networks | Bitcoin only. |
| Platforms | Hardware device plus mobile app for iOS 15.2+ and Android 7.0+ with NFC. |
| Connectivity | NFC to the phone; USB-C charging; battery up to one year per charge. |
| Display | Current model has an OLED touchscreen to verify transactions and security settings on the device; first-generation devices have no screen. |
| Secure element | Hardware key generated and stored offline in a secure enclave and unlocked by fingerprint. |
| Multisig | Built-in 2-of-3 multisig with integrated inheritance to a beneficiary who has their own Bitkey. |
| Buy / sell | Bitcoin purchases and transfers through partners such as Cash App and Coinbase inside the app. |

## Security and audits

- Firmware, mobile app and server code are public on GitHub (proto-at-block/bitkey); the current LICENSE file is the MIT License from Block, Inc. When first published in February 2024 the code carried the Commons Clause restriction on commercial use.
- Server keys run in an AWS Nitro Enclave; server code changes require multi-engineer approval.
- Bitkey publishes fixed security bugs on a Security Updates page (BKS IDs); it lists eight entries from August and October 2026, each with stated customer impact. Bitkey does not currently pay bug bounties.
- On 2 August 2026 Block disclosed a relationship-enrollment bug (weak randomness in Recovery Contact and inheritance setup, reported on 1 August 2026); Block stated it had no evidence any customer was exploited and that spending keys were not affected.

## Security incidents

No security incident is recorded in the sources checked on 31 October 2026 (the company’s own channels and incident databases): [api.llama.fi/hacks](https://api.llama.fi/hacks), [rekt.news/leaderboard](https://rekt.news/leaderboard), [hacked.slowmist.io/search](https://hacked.slowmist.io/search/), [bitkey.world/security-updates](https://bitkey.world/security-updates), [bitkey.world/blog](https://bitkey.world/blog), [api.github.com/repos/proto-at-block/bitkey/secur](https://api.github.com/repos/proto-at-block/bitkey/security-advisories)

## Fees

| Parameter | Details |
|---|---|
| Device price | USD 250 for the Bitkey kit on the US site (as of 31 October 2026). |
| Returns | Unopened hardware can be returned within 14 days of delivery for a refund of the purchase price (not if paid in bitcoin). |

## History

| Date | Event |
|---|---|
| 16 March 2023 | Block announced the product name Bitkey. |
| 22 February 2024 | Block published the code for the firmware, app and server, plus hardware schematics. |
| 13 March 2024 | Bitkey left pre-orders (opened in December 2023) and started shipping. |
| 27 April 2026 | Second-generation Bitkey with a screen introduced. |
| 2 August 2026 | Disclosure of the relationship-enrollment bug and app patch. |

## Risks and caveats

- Only the user controls access to the keys; theft of the phone or hardware combined with recovery tools can be used to steal funds, according to the terms.
- Beta features may contain bugs that could lose some or all funds.
- Bitcoin only: other coins cannot be held.

## About the developer

- **Developer**: Block, Inc., the company behind Square and Cash App.
- **Legal entity**: Block, Inc. for US customers; Block Global B.V. for shipping addresses outside the United States.
- **Headquarters**: Block, Inc., 1955 Broadway, Oakland, California, USA.

## Official links

- Website: [bitkey.world](https://bitkey.world/)
- Source code: [github.com/proto-at-block/bitkey](https://github.com/proto-at-block/bitkey)
- Security: [bitkey.world/security-updates](https://bitkey.world/security-updates)
- Support: [support.bitkey.world](https://support.bitkey.world/)
- Blog: [bitkey.world/blog](https://bitkey.world/blog)

## Questions and answers

**Is Bitkey self-custodial?**

Yes. It is a 2-of-3 multisig wallet: the user holds the phone key and the hardware key, and Block's server key alone cannot move funds.

**Does Bitkey use a seed phrase?**

No. Recovery relies on the other two keys, an encrypted cloud backup of the app key, Recovery Contacts and an Emergency Exit Kit.

**Is Bitkey open source?**

Its firmware, app and server code are public on GitHub; the current licence file is MIT from Block, Inc.

**Which coins does Bitkey support?**

Bitcoin only.

**Who makes Bitkey and what does it cost?**

Block, Inc., the company behind Square and Cash App. The kit is listed at USD 250 on the US site (as of 31 October 2026).

## Sources

- [Bitkey — Home](https://bitkey.world/)
- [Bitkey — Product](https://bitkey.world/product)
- [Bitkey — Learning hub: Bitkey security](https://bitkey.world/learning-hub/bitkey-security)
- [Bitkey — Learning hub: How Bitkey works](https://bitkey.world/learning-hub/how-bitkey-works)
- [Bitkey — Security updates](https://bitkey.world/security-updates)
- [Bitkey — Terms of Service](https://bitkey.world/legal/terms-of-service)
- [Bitkey blog — Relationship-enrollment bug in Bitkey](https://bitkey.world/blog/relationship-enrollment-bug-in-bitkey)
- [Bitkey blog — Sharing the code behind Bitkey](https://bitkey.world/blog/sharing-the-code-behind-bitkey)
- [Bitkey blog — Bitkey starts shipping today](https://bitkey.world/blog/bitkey-starts-shipping-today)
- [Bitkey blog — Meet the new Bitkey](https://bitkey.world/blog/meet-the-new-bitkey)
- [Bitkey blog — You can call us Bitkey](https://bitkey.world/blog/you-can-call-us-bitkey)
- [GitHub — proto-at-block/bitkey](https://github.com/proto-at-block/bitkey)
- [GitHub — proto-at-block/bitkey LICENSE](https://github.com/proto-at-block/bitkey/blob/main/LICENSE)

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Page updated: 2026-10-31

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Source: https://revain.org/wallets/bitkey/