suitable programming language for cryptography algorithms I know as programming languages C and java , and I know that java is slow so for this reason it is not suitable for cryptography applications espacially low level programming (manipulating bits) , so for this reason I turned to C as programming language but C is difficult in some how especially for GUI (graphical interfaces) , inaddition to this there is no byte type . My question is can we integrate C to java . it means when preparing GUI I use java and when programming the application I use C it is my first suggestion for asking you if it is possible and if we will not have a slow runtime. secondly using delphi ruther than C and java so , please advice me I am in adeadline ,and i must take a decision.
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.