From the RFC (which you appear to be (mis)quoting) -- my highlighting:

This document describes the MD5 message-digest algorithm. The algorithm takes as input a message of arbitrary length and produces as output a 128-bit "fingerprint" or "message digest" of the input.

It is conjectured that it is computationally infeasible to produce two messages having the same message digest, or to produce any message having a given prespecified target message digest.

The MD5 algorithm is intended for digital signature applications, where a large file must be "compressed" in a secure manner before being encrypted with a private (secret) key under a public-key cryptosystem such as RSA.

Cryptographic hashes are supposed to prevent someone from doing either one.

Nowhere in that do I see MD5 described as a "cryptographic hash"? Any application that uses a "digital signature" as a "cryptographic hash" based upon "conjectured...computational infeasibility" is a misapplication of the algorithm.

If the application needs a "cryptographic hash", it should be using one.

There are more uses of MD5 than are dreamt of in your philosophy, Horatio.

Ah yes, my dear Josephine Hardy*, but how many of them are misuses?

Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
"Memory, processor, disk in that order on the hardware side. Algorithm, algorithm, algorithm on the code side." - tachyon

In reply to Re^8: On showing the weakness in the MD5 digest function and getting bitten by scalar context by BrowserUk
in thread On showing the weakness in the MD5 digest function and getting bitten by scalar context by grinder

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