decoding SHA256 Objective C

Question

Possible Duplicate:
iPhone/OS X LION: How to retrieve the decoded data from the CC_SHA256 encrypted data?

I am using this to endoce my string. How can i decode it ??

-(NSString*)sha256HashFor:(NSString*)input
{
    const char* str = [input UTF8String];
    unsigned char result[CC_SHA256_DIGEST_LENGTH];
    CC_SHA256(str, strlen(str), result);

    NSMutableString *ret = [NSMutableString stringWithCapacity:CC_SHA256_DIGEST_LENGTH*2];
    for(int i = 0; i<CC_SHA256_DIGEST_LENGTH; i++)
    {
        [ret appendFormat:@"%02x",result[i]];
    }
    return ret;
}

http://stackoverflow.com/questions/10174536/iphone-os-x-lion-how-to-retrieve-the-decoded-data-from-the-cc-sha256-encrypted — JaredH, Feb 26 '13 at 03:44

score 2 · Accepted Answer · answered Jan 18 '13 at 08:15

The SHA (Secure Hash Algorithm) is one of a number of cryptographic hash functions. A cryptographic hash is like a signature for a text or a data file. SHA-256 algorithm generates an almost-unique, fixed size 256-bit (32-byte) hash. Hash is a one way function – it cannot be decrypted back. This makes it suitable for password validation, challenge hash authentication, anti-tamper, digital signatures.

Hope this info helps you..

decoding SHA256 Objective C

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