Cryptography

Introduction to Verifiable Delay Functions (VDFs)

Trail of Bits
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 […]

Fault Analysis on RSA Signing

Aditi Gupta
This spring and summer, as an intern at Trail of Bits, I researched modeling fault attacks on RSA signatures. I looked at an optimization of RSA signing that uses the Chinese Remainder Theorem (CRT) and induced calculation faults that reveal private keys. I analyzed fault attacks at a low level rather than in […]

You could have invented that Bluetooth attack

Trail of Bits
A serious bluetooth bug has received quite a bit of attention lately. It’s a great find by Biham and Newman. Given BLE’s popularity in the patch-averse IoT world, the bug has serious implications. And yet, it’s remarkably clean and simple. Unlike many elliptic curve bugs, an average human can totally understand the bug and how […]

Start using the Secure Enclave Crypto API

tl;dr – Tidas is now open source. Let us know if your company wants help trying it out. When Apple quietly released the Secure Enclave Crypto API in iOS 9 (kSecAttrTokenIDSecureEnclave), it allowed developers to liberate their users from the annoyance of strong passwords or OAuth. That is, if the developers could make do without […]

Apple can comply with the FBI court order

Earlier today, a federal judge ordered Apple to comply with the FBI’s request for technical assistance in the recovery of the San Bernadino gunmen’s iPhone 5C. Since then, many have argued whether these requests from the FBI are technically feasible given the support for strong encryption on iOS devices. Based on my initial reading of […]

Let’s Encrypt the Internet

We’re excited to announce our financial support for Let’s Encrypt, the open, automated and free SSL Certificate Authority (CA) that went into public beta on December 3. With so much room for improvement in the CA space, Let’s Encrypt offers a refreshing, promising vision of encrypting the web. Expensive SSL certificates are holding back Internet […]

Hardware Side Channels in the Cloud

Sophia D'Antoine
At REcon 2015, I demonstrated a new hardware side channel which targets co-located virtual machines in the cloud. This attack exploits the CPU’s pipeline as opposed to cache tiers which are often used in side channel attacks. When designing or looking for hardware based side channels – specifically in the cloud – I analyzed a […]

Analyzing the MD5 collision in Flame

Alex Sotirov
One of the more interesting aspects of the Flame malware was the MD5 collision attack that was used to infect new machines through Windows Update. MD5 collisions are not new, but this is the first attack discovered in the wild and deserves a more in-depth look. Trail of Bits is uniquely qualified to perform this […]