suitable programming language for cryptography algorithms
You can call C from Java. You can call C libraries from just about anything. 

Java isn't suitable for some cryptographic applications because you can't guard against garbage collector attacks, not because it's slow. It's not particularly slow. C does have a byte type, it's called "char". Object Pascal (Delphi) isn't a systems programming language, and so shouldn't be used to implement a crypto library.

Finally, do not implement your own cryptographic algorithms. Use an existing library.