Key Management Considerations for Cloud Computing

---

Level of Protection

• Encryption keys must be secured at the same level of control or higher as the data they protect

Key Recovery

• need to have the ability to recover keys in case original user leaves the company, loses password, etc.
• process usually entails multiple people
  • each has a portion of the key
• uses a key escrow system

Key Distribution

• Out-of-band key distribution can be a good idea
• in cloud, usually natively support key distribution
• may need to create keys locally, then upload them
• may use a cloud key management service

Key Revocation

• organization needs a process for suspending a key or a user’s ability to use a key
• keys are marked as revoked
• may use a centralized implementation

Key Escrow

• key escrow is used to hold keys in a secure way so that they can be recovered by authorized parties
• copy of a key is held by a trusted third party in a secure environment
• BitLocker keys for Windows workstations are often escrowed

Key Lifetime

• Keys shouldn’t live forever
• determining key life is an important part of the security design process
• best practices are found in NIST’s key management guidelines

Outsourcing Key Management

• keys should not be stored with the data they are protecting
• don’t make access to keys readily available without authorization and need to know
• in cloud computing, preferable to store keys other than cloud provider’s data center
  • organization itself can retain keys
    • requires infrastructure and skilled personnel
  • can use a CASB
    • third party organization that handles IAM and key management services for cloud customers
    • cost of CASB is lower than managing keys yourself
    • e.g.,
      • Zscaler
      • Netskope
      • McAfee’s Enterprise CASB tool