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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 page provides documentation for the \u003ccode\u003eSourceEncryptionKey\u003c/code\u003e struct within the Google Cloud Storage C++ client library.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation includes links to various versions of the \u003ccode\u003eSourceEncryptionKey\u003c/code\u003e struct, ranging from the latest release candidate (2.37.0-rc) down to version 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eSourceEncryptionKey\u003c/code\u003e is an optional parameter for rewrite operations, used to define the Customer-Supplied Encryption Key (CSEK) for the source object when rewriting it.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation details two static functions for creating a \u003ccode\u003eSourceEncryptionKey\u003c/code\u003e: \u003ccode\u003eFromBinaryKey\u003c/code\u003e which takes a 32-byte binary key, and \u003ccode\u003eFromBase64Key\u003c/code\u003e that accepts a base64-encoded key.\u003c/p\u003e\n"],["\u003cp\u003eIt is emphasized that care must be taken to save and protect these keys, as the data is not recoverable if they are lost, and developers are directed to external documentation for a description of how Customer Supplied Encryption Keys are used in GCS.\u003c/p\u003e\n"]]],[],null,[]]
