Envelope encryption plays a critical role in network security by adding an extra layer of protection for sensitive data. It involves encrypting data with a data key, and then encrypting that data key itself with a master key. This two-step process ensures that even if the data key is exposed, the actual data remains secure because it can only be decrypted with the master key, which is typically stored in a secure key management system.
For example, when a cloud application stores user data, it first generates a random data key to encrypt the data. Then, it encrypts this data key using a master key stored in a key management service (KMS). The encrypted data key is stored alongside the encrypted data. When the application needs to access the data, it retrieves the encrypted data key from the KMS, decrypts it, and then uses the data key to decrypt the actual data.
In the context of cloud services, Tencent Cloud's Key Management Service (KMS) provides secure master key storage and management, enabling envelope encryption for data at rest and in transit. This ensures compliance with security best practices and protects against unauthorized access.