# Hardware security module (HSM)

A hardware security module (HSM) is a tamper-resistant physical device that generates, stores, and uses cryptographic keys inside a certified hardware boundary, so keys never exist in readable form outside it. In digital asset custody, FIPS-certified HSMs are the hardware root of trust for private keys.

## Why banks anchor custody on HSMs

HSMs are the same class of hardware banks already trust for payments and PKI, certified to FIPS 140 levels, auditable, and operable entirely inside the bank's own data centers. They support offline signing, audited key ceremonies, and, decisively for the coming decade, every post-quantum signature family.

Taurus-PROTECT uses FIPS 140-2 Level 3 HSMs as the root of trust, with state-of-the-art MPC algorithms available on top where distributed approval is desired.

FAQ:

- HSM or MPC: which should a bank choose? They answer different questions. The HSM is where complete keys live, under bank control and certification; MPC distributes approval across parties. A sovereignty-first architecture uses the HSM as root of trust and adds MPC on top, which is the Taurus approach.

Related: https://www.taurushq.com/protect/ https://www.taurushq.com/glossary/fips-140/ https://www.taurushq.com/glossary/post-quantum-cryptography/

Learn more: https://www.taurushq.com/glossary/hardware-security-module-hsm/