The AI does not hate you, nor does it love you, but you are made out of atoms which it can use for something else.

Eliezer Yudkowsky in Artificial Intelligence as a Positive and Negative Factor in Global Risk (PDF)

Security is a process, not a product

Bruce Schneier in Secrets & Lies

Security is a chain; it's only as secure as the weakest link

Bruce Schneier in Secrets & Lies

What can be asserted without evidence can be dismissed without evidence

Christopher Hitchens in Hitchens's razor

There comes a point when it (General AI) becomes extremely dangerous, and that point is as soon as you switch it on.

Rob Miles in Deadly Truth of General AI? - Computerphile

It is important to view knowledge as sort of a semantic tree — make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to.

Elon Musk

The computer scientist Donald Knuth was struck that “AI has by now succeeded in doing essentially everything that requires ‘thinking’ but has failed to do most of what people and animals do ‘without thinking’—that, somehow, is much harder!

Donald Ervin Knuth in Superintelligence: Paths, Dangers, Strategies (ISBN: 978-0199678112)

Clarke's three laws

  1. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
  2. The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
  3. Any sufficiently advanced technology is indistinguishable from magic.
Arthur C. Clarke in Clarke's three laws

Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety.

Benjamin Franklin

The only reason coders’ computers work better than non-coders’ computers is coders know computers are schizophrenic little children with auto-immune diseases and we don’t beat them when they’re bad.

Peter Welch in Programming Sucks

You can't try to treat IT guys like they're a constricted cog in the normal bureaucratic flow of company. The more you try to punish them and make them conform the less they'll be willing to go above and beyond for you or the company. You have to communicate with IT guys like they're boys at play. What they do can get extremely complicated and infuriatingly frustrating, but they do it because they enjoy it. If you take the joy out of their work then you take away the creative efforts that they would otherwise put into their projects.

/u/n0vat3k in Using security clearance to my advantage

When you do things right, people won't be sure you've done anything at all.

Futurama s03e20


This domain is a technical demo of the latest (security) practices for the web. And my hobby...

This domain implements all of the mentioned security features mentioned below. Feel free to inspect the implementation and if you find issues or have questions, my contact information is at the end of the page.

HTTP Strict Transport Security (HSTS) (with preloading)

If you think for a second, what do you type in your address bar when you go to your bank, is it the full url with https://? no, noone does that, you'd type or similar. Bookmarked? How did you make the bookmark?

Without HSTS the browser will then do a simple unencrypted HTTP request which is easily intercepted by any MITM and he then owns the entire connection and is able to say anything he wants to the client. For example, instead of redirecting the user to HTTPS, just connect himself to the HTTPS page and proxy it to the user over HTTP, intercepting anything he wants or even injecting his own date into requests, the sky is the limit.

With HSTS, when the browser receives a request for HTTP on a HSTS protected domain, it will issue a Status Code: 307 Internal Redirect that never reaches the server or opens any connection to the HTTP version of the link, the user is protected without even noticing and is suddenly on a HTTPS encrypted connection.

An issue is the first request, the user is not protected until he gets the header over a valid HTTPS connection, which is what preloading is for, it is a signal that allows browser vendors to include a domain with the HSTS flag already set in browser updates, protecting the first request too. But it applies to entire domains and all subdomains so companies are nervous to implement it.

A major benefit is that this signal indicates to browsers that this domain must always be loaded securely and it allows them to REMOVE the "proceed anyway" method that oh so many users just click blindly without reading. You can see that in action here.

This attack was published in 2009 by Moxie Marlinspike, HSTS was published later that same year due to the seriousness of this attack.

Content Security Policy (CSP) with a strict policy

Do you have random CSS and JavaScript all over the place, maybe even inside your HTML directly, bad news, you are very probably vulnurable to XSS.

CSP lets you whitelist sources of images, scripts and styles, it blocks all "unsafe-inline" styles and scripts by default and allows you to make user browsers report when those whitelists are violated when they block those resources.

Implementing CSP is more than just flicking a switch like HSTS, you need to know your application pretty well, using inline styles or scripts is out of the question, eval is completely dead, so is insertRule and more unsafe stuff.

Just put a report-only CSP with the tightest policy: default-src 'none'; frame-ancestors 'none'; form-action 'none'; block-all-mixed-content; sandbox allow-scripts allow-same-origin; disown-opener; base-uri 'none';

After loading that once, you'll see that it blocks literally everything, that policy even blocks your favicon, so start with finding out where it is loaded, on your domain? Cool, add a img-src 'self'; and move on to the next, repeat until no blocks remain.

If you need unsafe-* policies, that's fine, just be aware of them and make it a goal of limiting it as much as possible and make an internal ticket to fix that issue!

When you are done, add a report-to and report-uri to your Sentry instance or similar and you are ready!

Subresource Integrity (SRI) (part of CSP needs special mention)

Whenever you include CSS or JavaScript in your page, you point it to a link and pray it loads correctly and has no malware or cryptocoin miners or similar, right?

Well, if you use SRI, you can be assured that only the file you specified gets loaded and if it fails, you can either just block it, breaking that resource, or fall back on a known safe file on your local server!

Loading any resource from a third party is always risky, not only because they can track your users, but they could replace a useful script, like a useful text-to-speech script, with a crypto-coin miner, perhaps even without breaking the text-to-speech feature!

That is exactly why SRI was created, to be able to include resources without having to trust the third party too much. You still have to trust that he isn't tracking your users, but that's what privacy policies and privacy laws are for, right?

Domain Name System Security Extensions (DNSSEC)

DNSSEC is a way to sign your DNS zone so that your users can receive information from DNS and be able to verify that the records received are really from your dns and not some attack.

The biggest challenge in getting DNSSEC is software, both your authoritative DNS server needs to serve it correctly but users are not protected by it unless their resolver also verify the DNSSEC information.

DNS Certification Authority Authorization (CAA)

CAA records in DNS are used by Certificate Authorities to decide if they are permitted to create certificates for your domain, they contain a list of the allowed CAs.

They are used only by the CAs themselves for verification during certificate issuance. And as such are a very weak form of protection from a hostile CA.

OCSP Stapling (with must-staple)

The Online Certificate Status Protocol is a method of checking whether a certificate has been revoked, but due to scaling problems with the ever increasing amount of HTTPS everywhere, they all implement a soft-fail on pretty much all errors, and some clients don't even bother checking at all so they introduced OCSP Stapling where the server serving the certificate includes a signed OCSP signature from the CA along with the certificate itself.

Now that's great, the client verifies it and life is good, but if the key ever gets stolen, then the thief can just, not send the stapled OCSP response to clients and they are none the viser.

That's where must-staple comes in, it is a field in the certificate that states that stapling is mandatory and skipping it is never okay.

no-referrer Referrer-Policy

Whenever a user clicks a link, he will send a request to the target that contains a Referrer header, that header can contain secret or private information such as query parameters.

Almost nobody uses the referrer for anything except tracking, so setting a policy of no-referrer is almost always okay.

Cross-origin resource sharing (CORS)

A good CORS policy is a method of preventing other websites from embedding your scripts and stealing your users cookies.

Other features of note

Fun security scanners

Who are you?

My name is Gunnar Guðvarðarson and my job is as a Network Administrator and DevOps at a company here in Iceland.

If you want to get in touch, my email address can be found in my PGP key.