Any wordpress developers here? I want to migrate a custom database

Question

Any wordpress developers here? I want to migrate a custom database

to wordpress.
1. What encryption/hashing method wordpress is using(so I can ask the users to update their passwords and hash it using same method as wordpress)
2. I see that wordpress is using kind of meta/value way instead of using static column name(in the database) but then it has some weird format, {a:3:"abc:123",.....}
is there a way to generate that format?

I tried reading but no luck ...