Help Center> Data Encryption Workshop> Service Overview> KMS> Functions
Updated on 2023-08-09 GMT+08:00
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Functions

KMS is a secure, reliable, and easy-to-use cloud service that helps users create, manage, and protect keys in a centralized manner.

It uses Hardware Security Modules (HSMs) to protect keys. All CMKs are protected by root keys in HSMs to avoid key leakage. The HSM module meets the FIPS 140-2 Leave 3 security requirements.

It also controls access to keys and records all operations on keys with traceable logs. In addition, it provides use records of all keys, meeting your audit and regulatory compliance requirements.

Functions

  • On the KMS console, you can perform the following operations on CMKs:
    • Creating, querying, enabling, disabling, scheduling the deletion of, and canceling the deletion of CMKs
    • Modifying the alias and description of CMKs
    • Using the online tool to encrypt and decrypt small volumes of data
    • Adding, searching for, editing, and deleting tags
    • Creating, canceling, and querying grants
  • You can use the API to perform the following operations:
    • Creating, encrypting, or decrypting data encryption keys (DEKs)
    • Retiring grants
    • Signing or verifying the signature of messages or message digests
    • Generating and verifying message authentication codes.

    For details, see the Data Encryption Workshop API Reference.

  • Generate hardware true random number.

    You can generate 512-bit random numbers using the KMS API. The 512-bit hardware true random numbers can be used as or serve as basis for key materials and encryption parameters. For details, see the Data Encryption Workshop API Reference.

Key Algorithms Supported by KMS

Symmetric keys created on the KMS console use the AES algorithm. Asymmetric keys created by KMS support the RSA and ECC algorithms.

Table 1 Key algorithms supported by KMS

Key Type

Algorithm Type

Key Specifications

Description

Application Scenario

Symmetric key

AES

AES_256

AES symmetric key
  • Data encryption and decryption
  • DEKs encryption and decryption
    NOTE:

    You can encrypt and decrypt a small amount of data using the online tools on the console.

    You need to call APIs to encrypt and decrypt a large amount of data.

Symmetric key

AES
  • HMAC_256
  • HMAC_384
  • HMAC_512

HMAC symmetric key

Generates and verifies a message authentication code

Asymmetric key

RSA
  • RSA_2048
  • RSA_3072
  • RSA_4096

RSA asymmetric password
  • Digital signature and signature verification
  • Data encryption and decryption
    NOTE:

    Asymmetric keys are applicable to signature and signature verification scenarios. Asymmetric keys are not efficient enough for data encryption. Symmetric keys are suitable for encrypting and decrypting data.

ECC
  • EC_P256
  • EC_P384

Elliptic curve recommended by NIST

Digital signature and signature verification

Table 2 describes the key wrapping encryption and decryption algorithms supported by imported keys.

Table 2 Key wrapping algorithms

Algorithm

Description

Configuration

RSAES_OAEP_SHA_256

RSA algorithm that uses OAEP and has the SHA-256 hash function

Select an algorithm based on your HSM functions.

If the HSMs support the RSAES_OAEP_SHA_256 algorithm, use RSAES_OAEP_SHA_256 to encrypt key materials.

NOTICE:

The RSAES_OAEP_SHA_1 algorithm is no longer secure. Exercise caution when performing this operation.

RSAES_OAEP_SHA_1

RSA algorithm that uses Optimal Asymmetric Encryption Padding (OAEP) and has the SHA-1 hash function
Parent topic: KMS