The 1337 PNG Hashquine, David Buchanan, Hashquine

A hashquine is a fun way to show off your crypto-tricks — It’s a file that contains its own hash. In some file types it’s trivial, you just pick the hash to hit, and then put random data in a comment or other invisible field till you get a collision. A Python script that prints its own hash would be easy. But not every file type is so easy. Take PNG for instance. these files are split into chunks of data, and each chunk is both CRC-32 and adler32 checksummed. Make one change, and everything changes, in three places at once. Good luck finding that collision. So how exactly did [David Buchanan] generate that beautiful PNG, which does in fact md5sum to the value in the image? Very cleverly.

Thankfully [David] shared some of his tricks, and they’re pretty neat. The technique he details is a meet-in-the-middle hack, where 36 pairs of MD5 collision blocks are found, with the understanding that these 36 blocks will get added to the file. For each block, either A or B of the pair will get plugged in at that location, and the md5sum won’t change. It’s a total of 2^36 possible combinations of these blocks, which is more computation than was practical for this particular hack. The solution is to pre-compute the results of every possible combination of the first 18 blocks, and store the results in a lookup table. The second half of the collisions are run backwards from a target CRC value, and the result checked against the lookup table. Find a hit, and you just found a series of blocks that matches both your target md5sum and CRC32 results.

Thanks to [Julian] for the tip! And as he described it, this hack is one that gets more impressive the more you think about it. Enjoy!

TECH NEWS RELATED

How to Use the ”Show Windows” Button on Your Chromebook

The “Show Windows” key has a rectangle and two vertical lines to the right. The key is on the top row of your Chromebook’s keyboard, between the full-screen and brightness reduction keys. It doubles as the F5 or Refresh key and is sometimes called the Windows Switcher, Overview, or Launcher ...

View more: How to Use the ”Show Windows” Button on Your Chromebook

The 10 best Water-type Pokémon in Pokémon Scarlet and Violet

Screenshot by Gamepur There are numerous Pokémon you can choose to take with you on your adventure in Pokémon Scarlet and Violet. The Pokémon you pick to bring with you will be used in dozens of battles, taking on the toughest trainers and Gym Leader challenges the Paldea region ...

View more: The 10 best Water-type Pokémon in Pokémon Scarlet and Violet

Where to find Wingull in Pokémon Scarlet and Violet

Screenshot by Gamepur Wingull has been a good early choice to add to your Pokémon team for a while. It’s Flying and Water typing lets you cover two areas of popular coverage until you get better options later on. Even if all you want to do is fill out ...

View more: Where to find Wingull in Pokémon Scarlet and Violet

Popular Ski App Slopes Adds Apple Watch Ultra Action Button Support

Popular skiing and snowboarding app Slopes over the weekend added support for the Apple Watch Ultra’s Action Button, making it one of the few third-party apps with native support for the feature. ‌Apple Watch Ultra‌ owners can program the Action Button to start a workout using the Slopes app, making ...

View more: Popular Ski App Slopes Adds Apple Watch Ultra Action Button Support

Gary Vee-Backed NFT Startup Candy Digital Cuts Staff in Mass Layoffs

The company, valued at $1.5 billion, is backed by Fanatics and was co-founded by Gary Vaynerchuk and Mike Novogratz.

View more: Gary Vee-Backed NFT Startup Candy Digital Cuts Staff in Mass Layoffs

Amazon offering rare $20 discount on Switch games like Smash Bros., Mario Kart

Super Smash Bros. Ultimate and Mario Kart 8 Deluxe almost never go on sale

View more: Amazon offering rare $20 discount on Switch games like Smash Bros., Mario Kart

Apple TV+ offering Ryan Reynolds for Cyber Monday

Who needs a discount on the streaming service when we can get Reynolds himself?

View more: Apple TV+ offering Ryan Reynolds for Cyber Monday

Where to find Veluza in Pokémon Scarlet and Violet

Screenshot by Gamepur Of the many new Pokémon added in Pokémon Scarlet and Violet, there are not many that look as intimidating as Veluza. The Jettison Pokémon is a Water and Psychic-type that is not a fish you would like to be swimming with in real life. That being ...

View more: Where to find Veluza in Pokémon Scarlet and Violet

Make a fake festival artist lineup with your most-played Spotify artists

BenQ, LG and Acer monitors receive the Cyber Monday treatment on Amazon

Tesla’s Model 3 could be redesigned to streamline manufacturing

Musk accuses Apple of hating ‘free speech’ in Twitter tirade sent from iPhone

How to tell if a Pokémon is shiny in Pokémon Scarlet and Violet

How to overclock laptop CPU safely and properly

Destiny 2 Triumph-hunter shadowevil completes all active objectives

Biggest Outflows in 12 Weeks as Investors Cash Out Following FTX Fall

How do auctions work in Pokémon Scarlet and Violet?

How to defeat Vali the Oath Guard in God of War Ragnarok

Apple Store Opening at Massive American Dream Mall Outside New York City

Code Vein (Mac) 

OTHER TECH NEWS

Top Car News Car News