encryption and decryption of spl chars

hi,

I have a string of Special characters.
I need to encrypt each of the special character to another value in the string, without repeatation, so that i can decrypt it back, for a particular seed value.


string_val=$%&()~'*,-/:;=?_

substr(string_val, mod (instr(string_val,curr_char) + 545,length(string_val)),1)

Curr_char is the value passed to get the encrypted one.

I am getting repeations (for eg., * and , are getting encrypted to $) due to which i am not able to decrypt.

can somebody suggest changes to the above query, so that there wont be any repeatations.

Why don't you just use the Obfuscation Toolkit?

Due to some bottlenecks in the application, i cannot use it.
I want a common algorith, which works same in front end and back end.

Your problem is that MOD( , n) gives values from 0 to n-1 and SUBSTR(x, 0, 1) is interpreted as SUSBTR(x, 1, 1). Check with this

Code:

---

declare
        string_val varchar(30) := '$%&()~''*,-/:;=?_';
        curr_char  varchar(1);
        out_line  varchar(100);
begin
        for i in 1..length(string_val) loop
                curr_char := substr(string_val, i, 1);
                out_line  := curr_char||' gives '||
                        substr(string_val, mod (instr(string_val,curr_char) + 545,length(string_val))+1,1);
                dbms_output.put_line(out_line);
        end loop;
end;
/

---

P.S. mod(545,16)=1 why be so complicated?

Thx Dapi