我存储的钥匙串数据是否仅限于我的应用程序？

Question

如果我在钥匙串中放入一些信息，那么我的应用程序是唯一能够访问该数据的应用程序，对吗？

Answer 1

The keychain data are shared across a developer's applications. From the apple documentation :

Keychain data for an app is stored outside of the app's sandbox. When the user backs up app data using iTunes, the keychain data is also backed up. Before iOS 4.0, keychain data could only be restored to the device from which the backup was made. In iOS 4.0 and later, a keychain item that is password protected can be restored to a different device only if its accessibility is not set to kSecAttrAccessibleAlwaysThisDeviceOnly or any other value that restricts it to the current device. Upgrading an app does not affect that app's keychain data.

Here is an example of sharing keychain information between applications.

Answer 2

The data an app puts into the Keychain is restricted to a single developer's apps. It can be shared by multiple apps by the same developer if desired or restricted to that app.

See WWDC13 2013 video "Protecting Secrets with the Keychain". You can access it either on you computer or on an iOS device with the Apple WWDC app.