I noticed some new quantum cryptography algorithms are being developed. I know very little about quantum computing but my understanding is that it will just be a much more powerful computer and therefore all the current key sizes that we use for cryptography will be rendered vulnerable to brute f...

Since the maximum authentication tag (MAC) size of AES-256-GCM is 16 bytes, And given that in one implementation, that breaking the MAC would break the security (ex. when a boolean 'decrypted' is used to either deny or allow access), Would using an additional MAC within the cipherText be a good i...