This is the implementation of Skein-256.
Compilation:
Just type 'make' in terminal
Execution:
the executable file generated is poi. So,just type ./poi
Input file:
the format is :
first 32 integers are byte values of plaintext(range:0 to 255)
second 32 integers are byte values of block cipher key(range:0 to 255)
third 128 integers are bit values of tweak(range:0 to 1)
Input file generator:
there is a file "filegen.c" which generates the input file.just compile it & run it in terminal. 
the output file generates byte values of enciphered text.
Note:the code is commented for better understanding.The code is slightly modified due to implementation difficulties.Please report the logical bugs to me.