The code originates from http://blog.andrewpaulsimmons.com/2008/07/md5-hash-on-iphone.html. I have copied it here for mirroring purposes. Please express your appreciations to Andrew for his efforts. #import <CommonCrypto/CommonDigest.h> NSString* md5( NSString *str ) { const char *cStr = [str UTF8String]; unsigned char result[CC_MD5_DIGEST_LENGTH]; CC_MD5( cStr, strlen(cStr), result ); return [NSS