Hi, I'm Scott Helme, a Security Researcher, Entrepreneur and International Speaker. I'm the creator of Report URI and Security Headers, and I deliver world renowned training on Hacking and Encryption.
Visit scotthelme.co.uk → RSS feedOn Hacker News Aug 2015 – Nov 2026
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One of eMudhra's certificate authority private keys is the number 4. Not a number that starts with 4, or the number 4 followed by a few hundred random digits, just, 4... Another one is 56, and another is 115. I know, because I recovered all of them from their
Let's Encrypt is an amazing organisation doing an amazing thing by providing certificates at scale, for free. The problem though was that they were the only such organisation for a long time, but I'm glad to say that the ecosystem is changing. It's always a good idea
A post called Passkeys are a trap. Do not use them. has been doing the rounds over the last few days, making it pretty high on Hacker News, and I've had it sent to me many times with an 'is this true?' kind of vibe. It's written for
As the use of HTTPS continues to increase across the Web, we need more support from Certificate Authorities that issue the certificates to make it all work. I'm a huge fan of Let's Encrypt and what they're doing, but if we want to encrypt the entire Web,
With slick marketing, catchy taglines and some pretty bold claims about their security, nomx claim to have cracked email security. Let's see if they have.
Let's Encrypt have announced that on July 8th, 2019 they will begin issuing new certificates from their own intermediate CA and not their current cross-signed intermediate. Here's what that means and what action, if any, site operators need to take…
After toiling with Cross-Site Request Forgery on the web for, well forever really, we finally have a proper solution, it's Same-Site Cookies.
A little while back I wrote a blog post about how "CSRF is dead". It focused on SameSite cookies, a powerful yet simple feature to protect your website against CSRF attacks. As powerful as it was, and as much as it will kill CSRF, you had to enable it on
Throughout 2025, I spoke a few times about our home energy solution, including our grid usage, our solar array and our Tesla Powerwall batteries. Now that I have a full year of data, I wanted to take a look at exactly how everything is working out, and, in alignment with
Regular readers will know that I'm very active in the CA / PKI space and even deliver a 2-day advanced training course [https://www.feistyduck.com/training/the-best-ssl-and-tls-training-in-the-world] on the topic. Over the last year or so I've been watching
We've identified 15,579 websites that are currently infected with malicious JavaScript and between them, we conservatively estimate that they receive more than 135 million visits every month. We know they're infected, and we have the evidence to back that up, but there's a problem: how on
On 30th September 2021, the root certificate that Let's Encrypt are currently using, the IdentTrust DST Root CA X3 certificate, will expire. You may or may not need to do anything about this Root CA expiring, but I'm betting a few things will probably break on that day
For those that read my blog often you may have seen me talk about EV certificates before. From a technical perspective there are many things that I don't agree with about EV certificates and from a non-technical perspective there are many things I don't like about the
Almost 2 years on from the last time I wrote about QWACs, I'm sadly not here to tell you that things have gone well since then. In fact, I'm actually here to tell you that things are not going well at all... QWAC Back in Jan 2022, I
Personal like or dislike of EV aside for a moment, we can all agree on what the name of EV certs implies. Organisations get their company details in the certificate and CAs have to do some extended validation of that data compared to a normal certificate. Turns out, that doesn'
HTTP Public Key Pinning is a very powerful standard that allows a host to instruct a browser to only accept certain public keys when communicating with it for a given period of time. Whilst HPKP can offer a lot of protection, it can also cause a lot of harm too.
In this blog I look at how widespread the usage of common security based HTTP response headers are in the Alexa Top 1 Million most visited sites.