how to encrypt a structure in C++

/*
The simplest type of data structure is a linear array
and simplest encrypt a structure in C++ similar this code :
*/
#include <iostream >
using std :: cout;
using std :: endl;
void encryptArray( char [ ] ); 
void decryptArray( char * eStr );
int main( )
{
	// create a string to Array
	char string[ ] = "this is a text string !";
	cout << "Original Array is: " << string << endl;
	encryptArray( string );
	// function encrypt Array( )
	cout << "encrypt Array string is: " << string << endl;
	decryptArray( string );
	//function decrypt Array( )
	cout << "after Array string is: " << string << endl;
	std::cin.get();
	return 0;

}// end of main
//-----------------------------------------------------
//encrypt Array data
void encryptArray (char e[] ) 
{
	for( int i=0; e[i] != '\0'; ++i ) ++e[i];
} // encrypt Array
//-----------------------------------------------------
//decrypt Array data
void decryptArray( char * eStr ) {
	for( ; * eStr != '\0'; ++ eStr ) --(* eStr);
}