# kSecUseDataProtectionKeychain A key whose value indicates whether to treat macOS keychain items like iOS keychain items. ``` let kSecUseDataProtectionKeychain: CFString ``` ## Discussion Set the value for this key to `true` in the query dictionary when accessing a macOS keychain item that behaves like an iOS keychain item. For example, use the data protection key when adding, searching for, or deleting an item to which the [`kSecAttrAccessible`](/documentation/Security/kSecAttrAccessible) or [`kSecAttrAccessGroup`](/documentation/Security/kSecAttrAccessGroup) attributes apply. The data protection key affects operations only in macOS. Other platforms automatically behave as if the key is set to `true`, and ignore the key in the query dictionary. You can safely use the key on all platforms. > Tip: > It’s highly recommended that you set the value of this key to `true` for all keychain operations. This key helps to improve the portability of your code across platforms. Use it unless you specifically need access to items previously stored in a legacy keychain in macOS. Items that you store or have stored in macOS with the [`kSecAttrSynchronizable`](/documentation/Security/kSecAttrSynchronizable) attribute set to `true` also behave like iOS keychain items. However, a `true` value for that attribute additionally causes iCloud to synchronize the item across all the user’s devices. Use [`kSecUseDataProtectionKeychain`](/documentation/Security/kSecUseDataProtectionKeychain) to get the iOS behavior without synchronization. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)