If you know the prime numbers divided in the encryption, you are not an outsider and the code is relatively easy to discern with powerful computers.
All encryption centers on the prime numbers.
And Apple knows what they are, and so does NSA. Otherwise the encryption could not be exported to ANYONE.
This illustrates you actually don't know everything about encryption by a long shot. Some levels of encryption would take thousands of years for current computer technology to crack.
Then you know nothing about encryption if you think encryption is based on prime numbers . . . This has absolutely nothing to do with export of data but rather with storage of encrypted data that has but a single key. Its not going anywhere.
Youre talking about two, or more, -key encryption, like public/private encryption, which is another animal completely.
This is a lockbox 256bit AES Advanced Encryption System (AES) that uses a key with a one-way algorithm applied to the data. You cannot use the algorithm and the data to calculate the key.
The key itself is constructed from four separate pieces plus the passcode hash. Only two of which are at all possibly knowable.
The final part is the unknowable one-way hash constructed and stored in another location for comparison by one of several algorithms randomly selected and not recorded to be burned into the Encryption Engine processor in the Secure Enclave, but the one-way hash recalculated anew each time its entered and compared to unlock the device, then when it has passed the comparison, the stored one will be used to construct the key.
This original stored passcode hash will be entangled with the other pieces of the stored data in the Secure Enclave by another random algorithm burned into the encryption engine to create the actual encryption key that will be used by the dedicated encryption engine processor to encrypt and decrypt the data. This is done every time.
None of this key construction data or the proper algorithms are available off the device in the proper unknowable configuration, so even were one to transmit the raw encrypted data elsewhere, without the hardware in this particular iOS device, it could never be unlocked.