Question

I am using MD5 algorithm for sync with server where I want to send data using MD5 algorithm.
I wrote following code-

NSString *string =  @"ABC";
    unsigned char *inStrg = (unsigned char*)[[string dataUsingEncoding:NSASCIIStringEncoding] bytes];
    unsigned long lngth = [string length];
    unsigned char result[MD5_DIGEST_LENGTH];
    NSMutableString *outStrg = [NSMutableString string];

    MD5(inStrg, lngth, result);

    unsigned int i;
    for (i = 0; i < MD5_DIGEST_LENGTH; i++)
    {
        [outStrg appendFormat:@"%02x", result[i]];
    }
    md5TextField.text = outStrg;

For decryption at server end I need its key through which MD5 text has been generated.
What will be its key?
Thanks in advance…

Answer 1

MD5 is a hashing function that is not reversible (and thus designed to be non-reversible). If you need a simple encryption, you should go for symmetric encryption using AES.

Chech out AES Encryption for an NSString on the iPhone for more infos.