An optional parameter to set the Customer-Supplied Encryption key for rewrite source object.
Application developers can generate their own encryption keys to protect the data in GCS. This is known as a Customer-Supplied Encryption key (CSEK). If the application provides a CSEK, GCS does not retain the key. The object data, the object CRC32 checksum, and its MD5 hash (if applicable) are all encrypted with this key, and the key is required to read any of these elements back.
Care must be taken to save and protect these keys, if lost, the data is not recoverable. Also, applications should avoid generating predictable keys, as this weakens the encryption.
This option is used only in rewrite operations and it defines the key used for the source object.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThis document details the \u003ccode\u003eSourceEncryptionKey\u003c/code\u003e structure within the Google Cloud Storage C++ library, covering version history and usage.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eSourceEncryptionKey\u003c/code\u003e structure is used in rewrite operations to define the Customer-Supplied Encryption Key (CSEK) for the source object.\u003c/p\u003e\n"],["\u003cp\u003eCSEKs allow users to generate their own encryption keys for data protection in Google Cloud Storage, where Google does not retain the key.\u003c/p\u003e\n"],["\u003cp\u003eThe document provides methods, such as \u003ccode\u003eFromBinaryKey\u003c/code\u003e and \u003ccode\u003eFromBase64Key\u003c/code\u003e, for creating \u003ccode\u003eSourceEncryptionKey\u003c/code\u003e instances using binary or base64-encoded keys, which must decode to exactly 32 bytes.\u003c/p\u003e\n"],["\u003cp\u003eThe page lists all versions available, ranging from 2.11.0 to 2.37.0-rc, with each version linking to its respective documentation.\u003c/p\u003e\n"]]],[],null,[]]
