Thanks, I will give it a try
Edit: from the man page: shc's main purpose is to protect your shell scripts from modification or inspection.
Well, tha's what I meant. I think that the program just does
system("....") /* your first shell statement */
system("...") /* second shell statement */
in a kind of "encrypted" way, but as it is using the shell, it cannot be faster than the script.
As keefaz said, I think that the better you can do is to rewrite your script(s) in perl or python.