Re: Fast hash of NSData?
Re: Fast hash of NSData?
- Subject: Re: Fast hash of NSData?
- From: ChanMaxthon <email@hidden>
- Date: Mon, 02 Dec 2013 22:25:30 +0800
What is wrong with a good ol' SHA-512?
Sent from my iPhone
> On 2013年12月2日, at 21:50, "Gerriet M. Denkmann" <email@hidden> wrote:
>
> Assuming that a typical image has 243.3 k Bytes, or 1 993 221 bits. And that a hash has 64 bits.
>
> Then there are 2^1 993 221 different images, and 2^64 hash values.
> One hash value is thus shared on average by 2^1 993 157 images. = (2^10)^199 315.7 = 10^600 000
>
> So it does not look so very unlikely that two different images might share a hash value.
>
> Or did I make some mistake?
>
> Gerriet.
>
>
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