https://miscreants.github.io/blog.trailofbits.com/authors/ben-perez/Recent content in Ben Perez on The Trail of Bits BlogHugoen-usMon, 14 Dec 2020 07:50:27 -0500https://miscreants.github.io/blog.trailofbits.com/2020/12/14/reverie-an-optimized-zero-knowledge-proof-system/Mon, 14 Dec 2020 07:50:27 -0500https://miscreants.github.io/blog.trailofbits.com/2020/12/14/reverie-an-optimized-zero-knowledge-proof-system/Zero-knowledge proofs, once a theoretical curiosity, have recently seen widespread deployment in blockchain systems such as Zcash and Monero. However, most blockchain applications of ZK proofs make proof size and performance tradeoffs that are a poor fit for other use-cases. In particular, these protocols often require an elaborate trusted setup phase and optimize for proof […]https://miscreants.github.io/blog.trailofbits.com/2020/05/21/reinventing-vulnerability-disclosure-using-zero-knowledge-proofs/Thu, 21 May 2020 07:50:27 -0400https://miscreants.github.io/blog.trailofbits.com/2020/05/21/reinventing-vulnerability-disclosure-using-zero-knowledge-proofs/We, along with our partner Matthew Green at Johns Hopkins University, are using zero-knowledge (ZK) proofs to establish a trusted landscape in which tech companies and vulnerability researchers can communicate reasonably with one another without fear of being sabotaged or scorned. Over the next four years, we will push the state of the art in […]https://miscreants.github.io/blog.trailofbits.com/2020/01/16/exploiting-the-windows-cryptoapi-vulnerability/Thu, 16 Jan 2020 11:28:34 -0500https://miscreants.github.io/blog.trailofbits.com/2020/01/16/exploiting-the-windows-cryptoapi-vulnerability/On Tuesday, the NSA announced they had found a critical vulnerability in the certificate validation functionality on Windows 10 and Windows Server 2016/2019. This bug allows attackers to break the validation of trust in a wide variety of contexts, such as HTTPS and code signing. Concerned? Get the important details and see if you’re vulnerable […]https://miscreants.github.io/blog.trailofbits.com/2019/10/30/how-safe-browsing-fails-to-protect-user-privacy/Wed, 30 Oct 2019 07:00:57 -0400https://miscreants.github.io/blog.trailofbits.com/2019/10/30/how-safe-browsing-fails-to-protect-user-privacy/Recently, security researchers discovered that Apple was sending safe browsing data to Tencent for all Chinese users. This revelation has brought the underlying security and privacy guarantees of the safe browsing protocol under increased scrutiny. In particular, safe browsing claims to protect users by providing them with something called k-anonymity. In this post we’ll show […]https://miscreants.github.io/blog.trailofbits.com/2019/09/11/crypto-2019-takeaways/Wed, 11 Sep 2019 06:50:16 -0400https://miscreants.github.io/blog.trailofbits.com/2019/09/11/crypto-2019-takeaways/This year’s IACR Crypto conference was an excellent blend of far-out theory and down-to-earth pragmatism. A major theme throughout the conference was the huge importance of getting basic cryptographic primitives right. Systems ranging from TLS servers and bitcoin wallets to state-of-the-art secure multiparty computation protocols were broken when one small sub-component was either chosen poorly […]https://miscreants.github.io/blog.trailofbits.com/2019/07/08/fuck-rsa/Mon, 08 Jul 2019 06:50:43 -0400https://miscreants.github.io/blog.trailofbits.com/2019/07/08/fuck-rsa/Here at Trail of Bits we review a lot of code. From major open source projects to exciting new proprietary software, we’ve seen it all. But one common denominator in all of these systems is that for some inexplicable reason people still seem to think RSA is a good cryptosystem to use. Let me save […]https://miscreants.github.io/blog.trailofbits.com/2018/10/22/a-guide-to-post-quantum-cryptography/Mon, 22 Oct 2018 06:50:12 -0400https://miscreants.github.io/blog.trailofbits.com/2018/10/22/a-guide-to-post-quantum-cryptography/For many high-assurance applications such as TLS traffic, medical databases, and blockchains, forward secrecy is absolutely essential. It is not sufficient to prevent an attacker from immediately decrypting sensitive information. Here the threat model encompasses situations where the adversary may dedicate many years to the decryption of ciphertexts after their collection. One potential way forward […]https://miscreants.github.io/blog.trailofbits.com/2018/10/12/introduction-to-verifiable-delay-functions-vdfs/Fri, 12 Oct 2018 06:50:10 -0400https://miscreants.github.io/blog.trailofbits.com/2018/10/12/introduction-to-verifiable-delay-functions-vdfs/Finding randomness on the blockchain is hard. A classic mistake developers make when trying to acquire a random value on-chain is to use quantities like future block hashes, block difficulty, or timestamps. The problem with these schemes is that they are vulnerable to manipulation by miners. For example, suppose we are trying to run an […]