After six months of work, DRM developer Maurice Heumann has successfully cracked Denuvo’s security system in Hogwarts Legacy. His goal was not piracy, but to study the intricacies of this security system. Therefore, in his blog, he deliberately omitted many details so as not to facilitate illegal hacking.
Heumann said Denuvo uses several methods to verify that Hogwarts Legacy is running legally. First, DRM creates a system “fingerprint” of the owner of the game, and to confirm the purchase, a Steam Ticket is used, which is sent to the Steam servers. Although the developer does not know for sure what exactly is happening on the servers, this is enough to understand how Denuvo works.
After verification of the Steam Ticket, a Denuvo Token is generated, tied to a specific PC fingerprint. This token is used to decrypt certain values during the game, allowing it to run. In addition, the game periodically checks the “fingerprint” to confirm security, which makes Denuvo extremely difficult to hack.
Six months later, Heumann was able to intercept Denuvo’s fingerprint on Hogwarts Legacy and use it to run the game on another PC. He used the Qiling framework to find most of the fingerprint triggers, which took two months. He discovered the third trigger by accident. Ultimately, using about 2,000 of his own patches and hooks, the developer was able to bypass most of Denuvo and run the game on a laptop using a token generated on a desktop PC.
Heumann also addressed the issue of Denuvo’s impact on gaming performance. He wanted to see if this DRM really reduces FPS as much as many people think. Unable to run tests, the developer examined the frequency of Denuvo calls, noting that infrequent security checks did not greatly impact performance even with slight slowdowns.
It turned out that the Denuvo code is executed in the game quite rarely – once every few seconds or when loading levels. This suggests that Denuvo is not a performance killer, contrary to popular belief. Heumann’s discovery confirms Denuvo’s official claims that their security does not impact gaming performance.
Although the developer was able to hack Denuvo in Hogwarts Legacy, the result was not perfect. The game still sometimes crashes because the main goal was to launch it and get to the main menu. Finding all the features of Denuvo and working around them is technically possible, but it will require a huge amount of time, which was not part of Heumann’s plans.
