Alan Cao For my winternship and springternship at Trail of Bits, I researched novel techniques for symbolic execution on cryptographic protocols. I analyzed various implementation-level bugs in cryptographic libraries, and built a prototype Manticore-based concolic unit testing tool, Sandshrew, that analyzed C cryptographic primitives under a symbolic and concrete environment. Sandshrew is a first step […]
TLS 1.3 represents the culmination of over two decades of experience in deploying large-scale transport security. For the most part it simplifies and improves the security of TLS and can act as a drop-in replacement for TLS 1.2. However, one new feature in the protocol represents a significant security risk to some existing applications: TLS […]
This year for CSAW CTF, Trail of Bits contributed two cryptography problems. In the first problem, you could combine two bugs to break DSA much like the Playstation 3 firmware hackers. The other challenge–-weirder and mathier–-was split into two parts: one for the qualifiers, one in finals. This challenge, “Holywater,” was some of the most […]
The Trail of Bits cryptographic services team contributed two cryptography CTF challenges to the recent CSAW CTF. Today we’re going to cover the easier one, titled “Disastrous Security Apparatus – Good luck, ‘k?” This problem involves the Digital Signature Algorithm (DSA) and the way an apparently secure algorithm can be made entirely insecure through surprising […]
Building and using cryptographic libraries is notoriously difficult. Even when each component of the system has been implemented correctly (quite difficult to do), improperly combining these pieces can lead to disastrous results. Cryptography, when rolled right, forms the bedrock of any secure application. By combining cutting-edge mathematics and disciplined software engineering, modern crypto-systems guarantee data […]
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 […]
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 […]
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 […]
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 […]
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 […]
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 […]
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 […]
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 […]
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 […]
