The four digit pin isn't to be confused with the passphrase that is used to encrypt/decrypt the keychain data. The pin is just an extra measure on top of your i

The four digit pin isn't to be confused with the passphrase that is used to encrypt/decrypt the keychain data. The pin is just an extra measure on top of your iCloud password to release your keychain data, along with SMS confirmation. A longer password or no password won't stop a government agency from being able to obtain the encrypted keychain data. I just confirmed that the encryption key is different from the PIN by going into keychain and viewing a password in the iCloud chain. It is indeed my much longer pass phrase that decrypts the data.