Despite the hype, Web3 offers fake decentralization and builds upon technology you could build without cryptocurrency.
Crackpot cryptography, overconfidence, and attempts to defraud governments and private-sector startups.
Just to assuage any panic, let me state this up front. If you’re reading this blog post wondering if your Lobste.rs account is at risk, good news: I didn’t publish it until after the vulnerability was mitigated, so you’re safe. You don’t need to change your passwords or anything. This write-up is purely for education […]
Wherein some furry casually saves a University tens of thousands of dollars on a NIST SP 800-171 audit they were doomed to fail anyway.
Canonicalization Attacks occur when a protocol that feeds data into a hash function used in a Message Authentication Code (MAC) or Digital Signature calculation fails to ensure some property that’s expected of the overall protocol. The textbook example of a canonicalization attack is the length-extension attack against hash functions such as MD5–which famously broke the […]
Last week, Floridians were startled by an emergency alert sent to all of our cell phones. Typically when this sort of alert happens, it’s an Amber Alert, which means a child was abducted. In Florida, we sometimes also receive Silver Alerts, which indicates that an Alzheimer’s or dementia patient has gone missing. (Florida has a […]
A question I often get–especially from cryptography experts: What is it with furries and Telegram? No, they’re almost certainly not talking about that. Most furries use Telegram to keep in touch with other members of our community. This leads many to wonder, “Why Telegram of all platforms?” The answer is simple: Stickers. Telegram was the […]
Previously on Dead Ends in Cryptanalysis, we talked about length-extension attacks and precisely why modern hash functions like SHA-3 and BLAKE2 aren’t susceptible. The art and science of side-channel cryptanalysis is one of the subjects I’m deeply fascinated by, and it’s something you’ll hear me yap about a lot on this blog in the future. […]
Responding to “Our cybersecurity ‘industry best practices’ keep allowing breaches”
Cryptographers and cryptography engineers love to talk about the latest attacks and how to mitigate them. LadderLeak breaks ECDSA with less than 1 bit of nonce leakage? Raccoon attack brings the Hidden Number attack to finite field Diffie-Hellman in TLS? And while this sort of research is important and fun, most software developers have much […]
Boycott Zed Shaw’s writing. (With bonus zero-days in his work.)
The fatal flaw of Birdwatch’s current design and how it can be fixed.
RSA is for encrypting symmetric keys, not entire messages. Pass it on.
The server for thedonald.win is hosted at 184.108.40.206. Read on to learn how I discovered this.
Earlier tonight, someone decided to change their Twitter handle and display name to impersonate a furry and solicit money to the scammer’s PayPal account. This is the same kind of lazy technique that script kiddies use to phish people for passwords, but more targeted. The goal is to dupe someone into sending the scammer money […]
Imagine you’re a software developer, and you need to authenticate users based on a username and password. If you’re well-read on the industry standard best practices, you’ll probably elect to use something like bcrypt, scrypt, Argon2id, or PBKDF2. (If you thought to use something else, you’re almost certainly doing it wrong.) Let’s say, due to […]
Governments are back on their anti-encryption bullshit again. Between the U.S. Senate’s “EARN IT” Act, the E.U.’s slew of anti-encryption proposals, and Australia’s new anti-encryption law, it’s become clear that the authoritarians in office view online privacy as a threat to their existence. Normally, when the governments increase their anti-privacy sabre-rattling, technologists start talking more […]
Earlier this week, security researcher Ryan Castellucci published a blog post with a somewhat provocative title: DKIM: Show Your Privates. After reading the ensuing discussions on Hacker News and Reddit about their DKIM post, it seems clear that the importance of deniability in online communications seems to have been broadly overlooked. Security Goals, Summarized When […]
Tonight on InfoSec Twitter, this gem was making the rounds: Hello cybersecurity and election security people,I sometimes embed your tweets in the Cybersecurity 202 newsletter. Some of you have a habit of swearing right in the middle of an otherwise deeply insightful tweet that I’d like to use. Please consider not doing this. Best,Joe Identity […]
This is the first entry in a (potentially infinite) series of dead end roads in the field of cryptanalysis. Cryptography engineering is one of many specialties within the wider field of security engineering. Security engineering is a discipline that chiefly concerns itself with studying how systems fail in order to build better systems–ones that are […]
Spyware written for educational institutions to flex their muscles of control over students and their families when learning from their home computer is still, categorically, spyware. Depending on your persuasion, the previous sentence sounds like either needless pedantry, or it reads like tautology. But we need to be clear on our terms. Educational spyware is […]
If you’re ever tasked with implementing a cryptography feature–whether a high-level protocol or a low-level primitive–you will have to take special care to ensure you’re not leaking secret information through side-channels. The descriptions of algorithms you learn in a classroom or textbook are not sufficient for real-world use. (Yes, that means your toy RSA implementation […]
I recently needed to find an image that I didn’t have saved on my computer in order to share with a group chat. For laughs. Naturally, I did the first thing most of us do when that happens: I typed the query into Google’s Image Search. To my dismay, all of the first results were […]
Historical Context of Iota’s Hash Functions Once upon a time, researchers discovered that the hash function used within the Iota cryptocurrency (Curl-P), was vulnerable to practical collisions. When pressed about this, the Iota Foundation said the following: In response to this research, the Iota developers threatened to sue the researchers. Iota replaced Curl-P-27 with a […]
If you see the letters GNU in a systems design, and that system intersects with cryptography, I can almost guarantee that it will be badly designed to an alarming degree. This is as true of GnuPG (and PGP in general) as it is of designs like the proposed GNU Name System (IETF draft) and cryptographic […]
A question I get asked frequently is, “How did you learn cryptography?” I could certainly tell everyone my history as a self-taught programmer who discovered cryptography when, after my website for my indie game projects kept getting hacked, I was introduced to cryptographic hash functions… but I suspect the question folks want answered is, “How […]
I probably don’t need to remind anyone reading this while it’s fresh about the current state of affairs in the world, but for the future readers looking back on this time, let me set the stage a bit. The Situation Today (By “Today”, I mean early May 2020, when I started writing this series.) In […]
A paper was published on the IACR’s ePrint archive yesterday, titled LadderLeak: Breaking ECDSA With Less Than One Bit of Nonce Leakage. The ensuing discussion on /r/crypto led to several interesting questions that I thought would be worth capturing and answering in detail. What’s Significant About the LadderLeak Paper? This is best summarized by Table […]
Update (2021-01-09): There’s a newer blog post that covers different CloudFlare deanonymization techniques (with a real world case study). Furry Twitter is currently abuzz about a new site selling knock-off fursuits and illegally using photos from the owners of the actual fursuits without permission. Understandably, the photographers and fursuiters whose work was ripped off by […]
Cryptographers around the world are still designing privacy-preserving contact tracing systems for combating the spread of COVID-19. Even though some papers have been published (one using zero-knowledge proofs, another based on blockchain (sigh)), the ink is still very wet. The first framework designed by Apple and Google needs work but was surprisingly not god-awful. That […]
Update (2020-04-29): Twitter has fixed their oversight. Anyone who set their custom gender to a long volume of text, should still have it set to a long volume of text. The original article follows after the separator. I was recently made aware of a change to Twitter, which exposes a new Gender field. If you’ve […]
There are two news stories today. Unfortunately, some people have difficulty uncoupling the two. The Team Fortress 2 Source Code has been leaked. Hackers discovered a Remote Code Execution exploit. The second point is something to be concerned about. RCE is game over. The existence of an unpatched RCE vulnerability, with public exploits, is sufficient […]