Google Workspace が提供する暗号化を使用する代わりに、独自の暗号鍵を使用して組織のデータを暗号化できます。Google Workspace クライアントサイド暗号化（CSE）では、ファイルが Google ドライブのクラウドベースのストレージに保存される前に、クライアントのブラウザでファイルの暗号化が処理されます。このため、Google のサーバーが暗号鍵にアクセスしてデータを復号することはできません。詳しくは、クライアントサイド暗号化についてをご覧ください。
この API を使用すると、カスタムの外部鍵サービスでデータを保護する最上位の暗号鍵を制御できます。この API を使用して外部鍵サービスを作成すると、Google Workspace 管理者はその鍵サービスに接続して、ユーザーに対して CSE を有効にできます。
重要な用語
Google Workspace クライアントサイド暗号化 API で使用される一般的な用語を以下に示します。
[[["わかりやすい","easyToUnderstand","thumb-up"],["問題の解決に役立った","solvedMyProblem","thumb-up"],["その他","otherUp","thumb-up"]],[["必要な情報がない","missingTheInformationINeed","thumb-down"],["複雑すぎる / 手順が多すぎる","tooComplicatedTooManySteps","thumb-down"],["最新ではない","outOfDate","thumb-down"],["翻訳に関する問題","translationIssue","thumb-down"],["サンプル / コードに問題がある","samplesCodeIssue","thumb-down"],["その他","otherDown","thumb-down"]],["最終更新日 2025-08-29 UTC。"],[[["\u003cp\u003eGoogle Workspace Client-side Encryption (CSE) allows you to encrypt your organization's data with your own keys, preventing Google servers from accessing or decrypting it.\u003c/p\u003e\n"],["\u003cp\u003eThis API enables you to manage the encryption keys via an external key service, giving you control over data access.\u003c/p\u003e\n"],["\u003cp\u003eCSE encrypts files in the user's browser before they are stored in Google Drive, ensuring only authorized users with access to your external key service can decrypt them.\u003c/p\u003e\n"],["\u003cp\u003eWhen a file is encrypted, Google Workspace generates a Data Encryption Key (DEK), which is then encrypted by your external key service and stored with the encrypted data.\u003c/p\u003e\n"],["\u003cp\u003eTo get started, you can configure your external key service and learn how to encrypt and decrypt data using the provided guides.\u003c/p\u003e\n"]]],["Google Workspace Client-side Encryption (CSE) allows users to encrypt data in their browser before cloud storage. This is achieved by using your own external Key Access Control List Service (KACLS). Google Workspace generates a Data Encryption Key (DEK) and sends it to your KACLS for encryption with a Key Encryption Key (KEK). Your service then returns the encrypted DEK to Google Workspace. This ensures that only users with KACLS access can decrypt the stored data.\n"],null,["# Build a custom key service for client-side encryption\n\nYou can use your own encryption keys to encrypt your organization's data,\ninstead of using the encryption that Google Workspace provides. With Google Workspace Client-side Encryption (CSE), file encryption is handled in the\nclient's browser before it's stored in Drive's cloud-based storage. That way,\nGoogle servers can't access your encryption keys and, therefore, can't decrypt\nyour data. For more details, see\n[About client-side encryption](https://support.google.com/a/answer/10741897#zippy=%2Cbasic-setup-steps-for-cse).\n\nThis API lets you control the top-level encryption keys that protect your data\nwith a custom external key service. After you create an external key service\nwith this API, Google Workspace administrators can connect to it and enable CSE\nfor their users.\n\nImportant terminology\n---------------------\n\nBelow is a list of common terms used in the Google Workspace Client-side Encryption API:\n\n*Client-side encryption (CSE)*\n: Encryption that's handled in the client's browser before it's stored in\n cloud-based storage. This protects the file from being read by the storage\n provider. [Learn more](https://support.google.com/a/answer/10741897#zippy=%2Chow-is-cse-different-from-end-to-end-ee-encryption)\n\n*Key Access Control List Service (KACLS)*\n: Your external key service that uses this API to control access to encryption\n keys stored in an external system.\n\n*Identity Provider (IdP)*\n: The service that authenticates users before they can encrypt files or access\n encrypted files.\n\n### Encryption \\& decryption\n\n*Data Encryption Key (DEK)*\n: The key used by Google Workspace in the browser client to encrypt the data\n itself.\n\n*Key Encryption Key (KEK)*\n: A key from your service used to encrypt a Data Encryption Key (DEK).\n\n### Access control\n\n*Access Control List (ACL)*\n: A list of users or groups that can open or read a file.\n\n*Authentication JSON Web Token (JWT)*\n: Bearer token ([JWT: RFC 7516](https://tools.ietf.org/html/rfc7516))\n issued by the identity partner (IdP) to attest a user's identity.\n\n*Authorization JSON Web Token (JWT)*\n: Bearer token ([JWT: RFC 7516](https://tools.ietf.org/html/rfc7516))\n issued by Google to verify that the caller is authorized to encrypt or decrypt a resource.\n\n*JSON Web Key Set (JWKS)*\n: A read-only endpoint URL that points to a list of public keys used to verify\n JSON Web Tokens (JWT).\n\n*Perimeter*\n: Additional checks performed on the authentication and authorization tokens\n within the KACLS for access control.\n\nClient-side encryption process\n------------------------------\n\nAfter an administrator enables CSE for their organization, users for whom CSE is\nenabled can choose to create encrypted documents using the Google Workspace\ncollaborative content creation tools, like Docs and Sheets, or encrypt files\nthey upload to Google Drive, such as PDFs.\n\nAfter the user encrypts a document or file:\n\n1. Google Workspace generates a DEK in the client browser to encrypt the\n content.\n\n2. Google Workspace sends the DEK and authentication tokens to your third-party\n KACLS for encryption, using a URL you provide to the\n Google Workspace organization's administrator.\n\n3. Your KACLS uses this API to encrypt the DEK, then sends the obfuscated,\n encrypted DEK back to Google Workspace.\n\n4. Google Workspace stores the obfuscated, encrypted data in the cloud.\n Only users with access to your KACLS are able to access the data.\n\nFor more details, see [Encrypt and decrypt files](/workspace/cse/guides/encrypt-and-decrypt-data).\n\nNext steps\n----------\n\n- Learn how to [configure your service](/workspace/cse/guides/configure-service).\n- Learn how to [encrypt \\& decrypt data](/workspace/cse/guides/encrypt-and-decrypt-data)."]]
