hey,
i am new to java and just looking at the caesar cipher encryption technique. i have written the encryption and decryption methods but i was wondering if this could be applied to selected files on my laptop somehow?
here is the encryption method:
BufferedReader in =new BufferedReader(new InputStreamReader(System.in)); //reader for keyboard
int key=10; //I have chosen 22 to be my key value but you can change this to any value between 0 and 25
System.out.println("Enter the text you wish to encrypt please: ");
String s=in.readLine(); // string s now contains the plaintext
for(int i=0;i<s.length();i++) //we look at the plaintext one character at a time
{
int current=s.charAt(i); //current holds the character as an int value - the ASCII value
if(current>64 && current<91) //if the character is an upper case letter
{
current=current+key; //add the key value onto the ASCII value
if(current>90) current=current-26; //if we've come off the end of the alphabet then we loop
} //back around by subtracting 26.
else if(current>96 && current<123) //if the character is a lower case letter
{
current=current+key;
if(current>122)current=current-26;
}
System.out.print((char)(current)); //now we print out the encrypted character or if the character
}System.out.println();
}
Here is the decryption
BufferedReader in =new BufferedReader(new InputStreamReader(System.in));
int key=16;
System.out.println("Enter the text you wish to encrypt please: ");
String s=in.readLine();
for(int i=0;i<s.length();i++)
{
int current=s.charAt(i);
if(current>64 && current<91)
{
current=current+key; //add the key value onto the ASCII value
if(current>90) current=current-26; //if we've come off the end of the alphabet then we loop
} //back around by subtracting 26.
else if(current>96 && current<123) //if the character is a lower case letter
{
current=current+key;
if(current>122)current=current-26;
}
System.out.print((char)(current));
}System.out.println();
}
Any help would be greatfully received, thank you
Marcello