How can the use of hashes as keys for encryption in PHP affect the security of the application?

Using hashes as keys for encryption in PHP can weaken the security of the application because hashes are typically used for integrity verification, not for encryption keys. It is crucial to use strong, randomly generated keys for encryption to ensure the security of the data. To fix this issue, generate a secure encryption key using a proper method like openssl_random_pseudo_bytes().

$encryptionKey = openssl_random_pseudo_bytes(32);