Apple responds about the iPhone 6 Error 53, saying that it is result of a deliberate security feature designed to protect users rather than being an error. Also Apple asks users to avoid using third party repairs to the Touch ID on the iPhone 6 and iPhone 6 Plus that will eventually brick the device in the next iOS update.
According to recent reports a large and yet growing number of iPhone users were facing the issue with their devices. The users were found attempting some kind of unofficial repair on their iPhone 6 and iPhone 6 Plus Touch ID. Following the repair, the affected users got the Error 53 while trying to update the firmware via iTunes.
Various site providing iPhone fixes have reported an overwhelming number of users discussing the Error 53. According to the iFixit their page on the Error 53 has attracted more than 183,000 hits which shows the huge concern with the issue.
According to the details the third party repairs actually change the iPhone home button and cable. After software upgrade the phone is checked for original parts and the phone is locked if any components other than original found. For many who have not faced the issue it was a little hard to believe the case until Apple confirmed it officially. According to Apple:
We protect fingerprint data using a secure enclave, which is uniquely paired to the Touch ID sensor. When iPhone is serviced by an authorised Apple service provider or Apple retail store for changes that affect the touch ID sensor, the pairing is re-validated. This check ensures the device and the iOS features related to touch ID remain secure. Without this unique pairing, a malicious touch ID sensor could be substituted, thereby gaining access to the secure enclave. When iOS detects that the pairing fails, touch ID, including Apple Pay, is disabled so the device remains secure.
According to Apple’s explanation, the fingerprint data on the iPhone is protected using a secure enclave which is paired with Touch ID sensor. The unequal pairing of secured fingerprint data with Touch ID sensor needs to be re-validated after it is repaired. Apple sees this check important for security of data on multiple iOS features.
This unique pairing stops any attempt of gaining access to the secure enclave through the malicious touch ID sensor. After the device is updated the iOS re-checks the pairing and disable the touch ID after it fails pairing to keep the device secure.