private static void decryption() {
		boolean d_loop = true;
		String fn= "pic", fex=".jpg";

		do {
			System.out.println("\n\n\n+==+ DECRYPTION +==+ \n\n"+
								"-- 1 - Begin decryption -- \n"+
								"-- 2 - Change file name (Currently:" +fn+fex+") -- \n"+
								"-- 3 - Go back -- \n");
			layer_2 = user_input.next();
			switch(layer_2) {
				case "1":
					final long startTimeDecr = System.currentTimeMillis();
		
					Decryption decr = new Decryption("rsa_private_key.txt");
					decr.decrypt(fn+"_fresh.encrypted", fn+"_fresh"+fex);
		
					final long endTimeDecr = System.currentTimeMillis();
					break;
					
				case "2": 
					boolean kbl_loop;	// loops until valid input is given
		
					System.out.println("Enter file name, hit enter and then write the file format (eg. .txt):");
					
					do{
						try {
							fn=user_input.next();
							fex = user_input.next();
							kbl_loop = false;
						}
						catch(Exception excptn) {
							System.out.println("Error: not an integer!\n"+
												"Try again: ");
							kbl_loop = true;
						}
					}while(kbl_loop);
					
							break;
							
						// Go back
					case "3":
							d_loop = false;
							break;
			}
		} while(d_loop);
	}