const
 csCryptFirst = 20;
 csCryptSecond = 230;
 csCryptHeader = 'Crypted';

type
 ECryptError = class(Exception);

function CryptString(Str:String):String;
var i,clen : Integer;
begin
 clen := Length(csCryptHeader);
 SetLength(Result, Length(Str)+clen);
 Move(csCryptHeader[1], Result[1], clen);
 For i := 1 to Length(Str) do
 begin
 if i mod 2 = 0 then
 Result[i+clen] := Chr(Ord(Str[i]) xor csCryptFirst)
 else
 Result[i+clen] := Chr(Ord(Str[i]) xor csCryptSecond);
 end;
end;

function UnCryptString(Str:String):String;
var i, clen : Integer;
begin
 clen := Length(csCryptHeader);
 SetLength(Result, Length(Str)-clen);
 if Copy(Str, 1, clen) < > csCryptHeader then
 raise ECryptError.Create('UnCryptString failed');

 For i := 1 to Length(Str)-clen do
 begin
 if (i) mod 2 = 0 then
 Result[i] := Chr(Ord(Str[i+clen]) xor csCryptFirst)
 else
 Result[i] := Chr(Ord(Str[i+clen]) xor csCryptSecond);
 end;
end;