What is the simplest but most reliable way to implement encryption and decryption of API keys?

Question

PHP

There are secret API keys that need to be stored in the database. This is a very important info, because. they allow you to access the wallets of your account on the cryptocurrency exchange. Therefore, they must be stored in encrypted form.
What is the best way to encrypt when writing to the database and decrypt when retrieving from there, using PHP?

Answer 1

php.net/manual/en/book.openssl.php