I'd like to encrypt Text with AES/CTR and a password defined by the user in java. I already checked the internet (and stackoverflow) for answers. The most used version is to hash the user pw with sha1 and take only the first 16bytes.

But I don't think this can be a good pratice.

1. sha1 is weak
2. taking only the first 16bytes makes the hash also weak and rise the chance for a collision (even with sha-256)

Is this really the best practice? Why? How can I do things better?

Some links to the articles I mentioned:

• https://stackoverflow.com/questions/3451670/java-aes-and-using-my-own-key
• https://howtodoinjava.com/security/java-aes-encryption-example/
• https://blog.axxg.de/java-aes-verschluesselung-mit-beispiel/