If you enter an incorrect iCloud Security Code too many times when using iCloud Keychain, your iCloud Keychain is disabled on that device, your keychain in the cloud is deleted, and you get one of these alerts:

• “Security Code Incorrectly Entered Too Many Times. Approve this iPhone from one of your other devices using iCloud Keychain. If no devices are available, reset iCloud Keychain.”
• “Your iCloud Security Code has been entered too many times. Approve this Mac from one of your other devices using iCloud Keychain. If no devices are available, reset iCloud Keychain.”

If you have access to another approved device that is using your iCloud Keychain

Follow these steps to create a new iCloud Security Code on your other device.

• Devices using iOS 7.0.3 or later:
  1. Go to Settings > iCloud > Account > Keychain.
  2. Tap Change Security Code.
  3. Enter your Apple ID password when asked.
  4. Enter a new iCloud Security Code. 
• Macs using OS X Mavericks:
  1. Choose Apple () menu > System Preferences, then click iCloud.
  2. Click Account Details.
  3. Click Change Security Code and enter a new iCloud Security Code.

Now return to the original device for which iCloud Keychain was disabled. Complete these steps to create a new iCloud Keychain in the cloud, which will contain the username, passwords, and other keychain items from this device.

• Devices using iOS 7.0.3 or later: Go to Settings > iCloud and turn on iCloud Keychain.
• Macs using OS X Mavericks: Choose Apple menu > System Preferences. Click iCloud, then select Keychain.

An approval notification will appear on the device that you used to create the new iCloud Security Code. After you've given your approval, the original device will be updated with your new iCloud Keychain.

If you don't have access to another approved device that is using your iCloud Keychain

Follow these steps to reset your iCloud Keychain.

• Devices using iOS 7.0.3 or later:
  1. Go to Settings > iCloud > Keychain, then tap “Approve with Security Code”.
  2. Tap “Forgot Code?” when you're asked to enter your iCloud Security Code.
  3. Tap Reset iCloud Keychain to replace your keychain in the cloud with the iCloud Keychain from your device.
  4. Tap Reset to confirm.
  5. Follow the onscreen instructions to create a new iCloud Security Code.
• Macs using OS X Mavericks:
  1. Choose Apple menu > System Preferences. Click iCloud, then select Keychain.
  2. Tap “Forgot Code?” when you're asked to enter your iCloud Security Code.
  3. Click Reset Keychain to replace your keychain in the cloud with the iCloud Keychain from your device.
  4. Click Reset to confirm.
  5. Follow the onscreen instructions to create a new iCloud Security Code.