GreHack CTF – Casting reverse challenge into cryptanalysis challenge​
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GreHack CTF – Casting reverse challenge into cryptanalysis challenge​

ByNabih Benazzouz

Grehack ctf WRITEUP Casting reverse challenge into cryptanalysis challenge In mid-November, I participated in the GreHack CTF with my team (Phreaks 2600), and the challenge I will present was one of the problems featured in the competition. Interestingly, only two other teams managed to solve it, this makes it a particularly intriguing challenge, categorized under…

Sponge Trouble: When Poseidon Gets Absorbed in Its Own Bugs
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Sponge Trouble: When Poseidon Gets Absorbed in Its Own Bugs

ByNabih Benazzouz

Poseidon Sponge Bugs in ArkWorks Avoiding Cryptographic Failures in Hashing We found two subtle yet impactful bugs in the ArkWorks library’s implementation of the Poseidon Sponge. This discovery highlights the complexity and precision required in cryptographic implementations. In this article, we’ll first explain what Poseidon Sponge is, how it works, and then delve into the…

gnark zkp consensus OOM cryptography
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Uncovering an Out of Memory Vulnerability in Gnark: How We Discovered CVE-2024-50354

ByPatrick Ventuzelo

Uncovering an Out of Memory Vulnerability in Gnark How We Discovered CVE-2024-50354 Last month (october 2024), LambdaClass and Fuzzinglabs teams discovered an Out of Memory (OOM) vulnerability within the Gnark library, one of the most popular Go library for zk-SNARKS. During the deserialization of Verifying Keys, we can trigger a fatal error that can lead…