MD5 Hash Broken via Collision Attack of Less Than $1

The MD5 hash collision attack that hijacked the Windows Update system back in 2012 was replicated with just 65 US cents worth of cloud computing fees, according to Nathaniel McHugh’s blog post.

The MD5 collision attack has been previously used by the Flame malware that spoofed its signing code with the one from Microsoft`s certificates using MD5 hash algorithm.

McHugh used an open source application dubbed HashClash and modified it to separate images to generate an identical MD5 hash.

“So I guess the message to take away here is that MD5 is well and truly broken,” McHugh said. “Whilst the two images have not shown a break in the pre-image resistance, I cannot think of a single case where the use of a broken cryptographic hash function is an appropriate choice.”

The hash collision attack took 10 hours using a GPU session from Amazon Web Services which cost 65 US cents plus tax. The MD5 hash algorithm issue is that anyone has the means to generate the same hash from two separate inputs.

McHugh also advised that “no one should be using MD5 for anything. However, old habits die hard and once upon a time MD5 seemed like a fast and secure hash function.”