HSM is a hardware security module that provides precise cryptographic key generation, protection in a secure environment, and cryptographic processing with these keys.
It is the common view of the authorities (PCI, NIST ...) that operations involving cryptographic operations such as payment, data security and electronic signature can not be done safely without using HSM.
HSMs are hardened, tamper-resistant hardware devices that strengthen encryption practices by generating keys, encrypting and decrypting data, and creating and verifying digital signatures. Some are certified at various FIPS 140-2 Levels. They are frequently used to:
- Meet and exceed established and emerging regulatory standards for cybersecurity
- Achieve higher levels of data security and trust
- Maintain high service levels and business agility
and 
brands.