I'm developing an application which will need to derive a private/public key pair from a user provided password, and then use the public key to encrypt some text (up to 1000 characters in length) such that it can only be decrypted by the paired private key. The password and private key will not be stored anywhere, so that nobody with access to the database can decrypt the text without the users' password. I know that I will need to use a KDF algorithm to generate the key, and some sort of public key encryption algorithm to encrypt/decrypt.
I know that there are several secure algorithms, but also several algorithms which are considered cracked and insecure. What are the most secure algorithms I can use for the KDF and encryption? What best practices should I follow to ensure that the data is as secure as possible?
I will be using the Java standard library implementations of the cryptographic algorithms.