Key Management Service API, gRPC: SymmetricCryptoService.Decrypt

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Updated at December 9, 2025

Decrypts the given ciphertext with the specified key.

gRPC request

{
  "key_id": "string",
  "aad_context": "bytes",
  "ciphertext": "bytes"
}

Field	Description
key_id	string Required field. ID of the symmetric KMS key to use for decryption. The maximum string length in characters is 50.
aad_context	bytes Additional authenticated data, must be the same as was provided in the corresponding SymmetricEncryptRequest. Should be encoded with base64. The maximum string length in characters is 8192.
ciphertext	bytes Required field. Ciphertext to be decrypted. Should be encoded with base64.

{
  "key_id": "string",
  "version_id": "string",
  "plaintext": "bytes"
}

Field	Description
key_id	string ID of the symmetric KMS key that was used for decryption.
version_id	string ID of the key version that was used for decryption.
plaintext	bytes Decrypted plaintext.