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[Tyler Close]

Jonathan Shapiro wrote:
> I am currently building a system in which I rely on being
> able to compute
> cryptographic hashes of the content using an algorithm that
> I specify.

It is an unfortunate thing that cryptographic hash functions and
hashtable hash functions are both called hash functions. They are two
very different activities with very different purposes. Hashtable hash
functions are used only for searching, whereas cryptographic hash
functions are used for integrity checking and identification.

It might be better if you think of cryptographic hashs as "message
digests", or MACs (Message Authentication Codes), instead of hashs.
This makes it clear that there are additional requirements for these
hashs than for hashtable hashs (requirements that a hashtable does not
need to meet).

Tyler


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