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

Visitor ratings: do you like Bitkey?

Key facts

Official site: 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

Who holds the keys — Bitkey
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

Features and supported networks — Bitkey
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.

Fees

Fees — Bitkey
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

History — Bitkey
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
Source code: github.com/proto-at-block/bitkey
Security: bitkey.world/security-updates
Support: support.bitkey.world
Blog: 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

How voting works

Votes are anonymous and carry no text. Each device has one vote per item; press the same button again to remove it. Cloudflare Turnstile checks that a person is voting. We keep a random device ID in a cookie and a salted hash of the IP address to limit abuse — no names, no accounts. Votes are visitors’ opinions, not investment advice.

Page updated: 2026-10-31