RFC2109, from 1997, had this:

8.3 Unexpected Cookie Sharing

A user agent should make every attempt to prevent the sharing of session information between hosts that are in different domains. Embedded or inlined objects may cause particularly severe privacy problems if they can be used to share cookies between disparate hosts. For example, a malicious server could embed cookie information for host a.com in a URI for a CGI on host b.com. User agent implementors are strongly encouraged to prevent this sort of exchange whenever possible.

It's really weird that they claim there privacy work started in 2015. Netscape Navigator add cross site cookie blocking at some point, and firefox has always (?) had it.

The innovation here seems to be that they further partition by the URL in the address bar.

It's frustrating that browsers have been fighting and losing this war for 25 years. (Presumably they still don't block browser fingerprinting, so sites will just move to that instead...)

It's not possible to block browser fingerprinting since it's a range of techniques and heuristics based on numerous features. There's no "turn off fingerprinting" button you can just press.

It is possible to enable obstacles to fingerprinting.

In Firefox, it is configuration entry

  privacy.resistFingerprinting

Some details (the list is not exhaustive):

> * Your timezone is reported to be UTC; * Not all fonts installed on your computer are available to webpages; * The browser window prefers to be set to a specific size; * Your browser reports a specific, common version number and operating system; * Your keyboard layout and language is disguised; * Your webcam and microphone capabilities are disguised; * The Media Statistics Web API reports misleading information; * Any Site-Specific Zoom settings are not applied; * The WebSpeech, Gamepad, Sensors, and Performance Web APIs are disabled, etc.

I’ve got this enabled - the only one that’s been more than a mild pain in the ass is the UTC timezone change. Always takes a minute to remember why a site is telling me my appointment is at 2:30 in the morning.

Is there a way to reset the timezone but have all the other protections? Timezone provides pretty low information relative to the pain it causes me when I show up to my meeting 5 hours later.

Just move to London

UK has daylight savings time. Better move to Iceland instead. They're always on UTC.

I have tried and tried to override this on a site-by-site basis

I tried setting:

privacy.resistFingerprinting.exemptedDomains to the domain

privacy.resistFingerprinting.testGranularityMask -> 4

I still get utc in slack

Whonix says hello. https://www.whonix.org/

I was planning to use it exclusively when I was working on a system to fight cartels, so I got pretty deep into these kinds of questions. Whonix has its own problems but it's the best solution available.

The communities are interesting too. One fellow was trying to download map data, which confused me initially. Why was he so fixated on maps? It's because if you're in the middle of a warzone, there's obviously no cell service, and it might be a few weeks before you reach an area with wifi. Remarkably prescient given that this was 2013 or so.

But you're right in general that there's no way to do it that isn't a pain in the ass for most people. "I can't resize my browser window? Really?"

I'm sure that the techniques used in Whonix can reduce the number of valuable features used in fingerprinting but you can't "solve" fingerprinting without every single user switching over to something like this.

It's not binary but it's unfair to say "it can't be done" it absolute can be made significantly better.

The strongest fingerprinting techniques use a lot of computing (e.g. font, canvas analysis) so they are expensive to use - no one wants to slow down their visitors by several seconds. The weaker fingerprint techniques can be easily patched and mocked it's just that it's a constant effort to keep up with them.

All it would take is 1 major browser to enable it by default to distrubt whole fingerprinting ecosystem to the point where it would be too expensive to effectively fingerprint people.

It's certainly possible to curtail fingerprinting.

Why is my browser reporting my resolution to the server? Why can't you just serve me HTML and let me render it how I damn well please?

> Why is my browser reporting my resolution to the server

The browser doesn’t need to report anything by default. You can get a reasonable estimate with CSS + JavaScript (e.g. using media queries to modify some observable properties on the basis of the screen width and then report what those properties are via a call to fetch)

Sounds like a really unique, fingerprintable way to browse.

Internet explorer used to ask the user before saving cookies.

And the server had to declare what cookies would be used for in machine readable form (P3P) which the browser used to decide if it want to allow the cookie (google blatantly lied)

And more recently DNT.

A graveyard of failed attempts at improving privacy

FIrefox used to ask, then it would ask if you set the right preference, and then it stopped asking entirely. I was very disappointed in them.

Why was it disappointing in them? Don't they need to compete with Chrome and Safari's UX, that just allow those cookies?

That's no reason to remove the preference that allowed people to re-enable the dialog box.

> Why weren’t separate cookie jars the default in the first place?

Tracking today is an interaction between cookies and pages, not really because cookies were designed to be shared between domains. Because of that, ads on web pages are a reason that information gets shared across sites. Any ad or other iFramed content that’s served on a site can get the domain name of where it’s be served from and then access the iFrame domain’s cookies, which enables tracking.

The cookie jar language might be a tiny bit oversimplifying/confusing in the sense that cookies are already separated from each other according to the cookie’s domain - they’re already in separate jars in a way, and this feature is changing how they partition the jars. Assuming even the most strict privacy settings, tracking cookies and scripts are often in iFrames and may not have the ability to directly read other cookies from the web site in your URL bar, and the web site might not be able read the tracking cookies. It’s not that cookies themselves are being shared per se. It’s that (say) Facebook is allowed to put an iFramed tracker on some site, and Facebook can then get a tracking blip when you visit that site and add it to a Facebook-only cookie. Total Cookie Protection is going to put cookies that only Facebook can see in a different jar for each separate site you visit, making it so that Facebook can’t read it’s own cookies across different sites.

The solution still seems to be to:

1. Use Firefox, block .js by default, and selectively allow.

2. Set browser to block cross-site cookies, and to purge all cookies when closing browser.

3. Avoid tabbed browsing, and restart browser after using a website.

I've been doing this since about 2006. It's inconvenient, but gives some peace of mind.

That’d certainly prevent most tracking, yeah. This new Firefox feature should make #2 and #3 unnecessary.

I think this feature by Firefox is great, and privacy options are getting objectively better, if slowly. But the cynic in me guessing that server side tracking methods are going to start getting secretly better, if they haven’t already.

I'm not sure about #3. there's still sessions, localstorage, indexDB, etc

I didn't mention #4 of also purging all that other stuff when the browser closes.

Honestly, try it with me - it's not so bad. 1, 2, 3, everybody now!

I don't really need to. With the extensions I use, every new tab I open is like a private windows, it has its own isolated environment.

And I can still keep sessions opened where I really need to

The solution is political action. You're describing a workaround that only a few of the most concerned people will be willing to use.

Agreed, the solution is to work with others toward a solution.

In my defense, I don't see it as a workaround - I wouldn't use it any other way.

There was a time when one didn't need to do this, but the internet has become more cumbersome to use. Easy-breezy... just make it muscle memory, and don't look back!

To reduce the burden use extension Temporary containers, so each tab opens into a clean environment.

And use Firefox container to auto-open domains on specific containers where you want to keep sessions or have a shared profile among various domains

How about just using the "Delete Cookies" -feature of the browser? And maybe there's a plugin that would make that one-click process?

I'd replace 3 with self-destructing cookies.

I just by default use private mode. Pretty sure in Safari that helps.

2 and 3 are "browse in private mode", to make thing simple.

> Total Cookie Protection is going to put cookies that only Facebook can see in a different jar for each separate site you visit, making it so that Facebook can’t read it’s own cookies across different sites.

Won't this break some basic features like being logged in to Facebook (or similar services, e.g. Disqus) for the purpose of embedded comment sections on other sites? They don't use cookies only for tracking buttons after all. It would be… annoying… for every site to require a separate login.

They handle it gracefully. As per their write-up[1]:

> In addition, Total Cookie Protection makes a limited exception for cross-site cookies when they are needed for non-tracking purposes, such as those used by popular third-party login providers. Only when Total Cookie Protection detects that you intend to use a provider, will it give that provider permission to use a cross-site cookie specifically for the site you’re currently visiting. Such momentary exceptions allow for strong privacy protection without affecting your browsing experience.

[1] https://blog.mozilla.org/security/2021/02/23/total-cookie-pr...

Yes, it might break embedded features like comments unless you whitelist the allowed uses. I would assume Firefox handles this thoughtfully, but I haven’t tried the new cookie jars yet, so I don’t know what the UI looks like or allows.

Elsewhere they mentioned that there are exceptions for "popular" SSO systems, but I have a hard time imagining any exception that would allow a shared login for Facebook comments while blocking Facebook tracking across sites. These are essentially the same mechanism.

Why can't the browser can handle the login?

They tried https://en.m.wikipedia.org/wiki/Mozilla_Persona

Yes. Hope so. What a bad idea that is.

The site owners place the Facebook crap on their site...therefore enabling Facebook to track you across any and all sites that embed the tracker. Facebook and other tracking companies are so ubiquitous (most sites have multiple trackers) that they end up getting a feed of Sally's activity across the web...via the cookie loophole.

Cookies need restricted to the URL in the address bar. Anything else is like a side effect or unintended and woefully non-transparent consequence of sneaky fucks harvesting your information (clicks, keystrokes, and metadata) via JavaScript and cookies.

There are legit cross-domain use cases. A good example is how someone here mentioned (comment seems deleted though) account sessions being shared between Atlassian products like JIRA and BitBucket.

The problem with that is domains are a poor way of representing ownership that can be trusted. If the web was rebuilt from scratch, a better approach might be to allow cookies to be shared between secure sites using the same certificate. But that adds more complexity that I'm not sure is worthwhile. The web can absolutely get away with not having shared cookies.

There’s no technical reason why this has to be hard. If jira was at jira.atlassian.com and bitbucket was bitbucket.atlassian.com, they would have the same origin, plus they would make the relationship between them visible to any moderately savvy user. It’s only complicated because they allow their marketing dept to make it complicated.

I think that’s unfair. By tying things to domains that way, you also make it potentially difficult to change URL structure (look at how long the various go.com domains lasted across all Disney/ABC properties. I know of teams that had very real problems years later b/c the infra was still based on domain stuff that was setup 15 years prior when the parent company thought internet portals were worth spending billions on), not to mention if you want to spin-off or sell an asset. Or if you acquire an asset!

To say nothing of SSOs, where you might not want to carry your login across, but you’d like to have the option of saying “yes, I’d like to use this account here too” and then authenticate.

Also if you sign into Google, notice you bounce through YouTube for what I assume to be similar reasons

You do realize acquisitions occur?

Business operation complications are not a valid reason for the violation of the rights of humans.

Cross-domain cookies are a tool that can be used for good or bad. It's a tradeoff to block them or not block them.

So use a 301 redirect.

you do realize reorganization occur after acquisitions?

There are also legit use cases for leaving all your doors unlocked. But they usually aren't really worth considering when you are installing your doors/locks.

Isn't this solved with a login redirect? Just return a signed ID and set up cookies on the other end with that. Granted, it's one more redirect per domain than before per login period, but that's hardly onerous.

Domains that want to collaborate together can still do so.

> allow cookies to be shared between secure sites using the same certificate

In some ways that will be less strict than Firefox's implementation. A CDN might have a certificate with hundreds of unrelated sites in it.

In some ways that will be more strict than Firefox's implementation. A site might want to serve large static files on static.foo.com but a secure login page on login.foo.com , and want to hand over the private key for static.foo.com to a CDN but not hand over the private key for login.foo.com .

> allow cookies to be shared between secure sites using the same certificate

Or maybe encrypting cookies using the site certificate, which would still allow cookies to be shared with domains having a different certificate, but the server needs the correct key for decryption.

Sounds like it'll make key rotation tricky.

Also it'll likely break javascript access to the cookies.

Ciphertext leaks information via its size and its presence / absence.

yeah and so? how is this information useful? if the actual useful information is encrypted, then size is meaningless as it is just random text until decrypted. presence/absence? you have a cookie or you don't?

You say the size is meaningless. But sometimes it may actually be meaningful. And presence/absence is information also. Not much, but it definitely exists.

In what way? If I'm storing 255 bytes of username/email/credentials/settings/etc, but pad in some fun way to 512 bytes prior to encryption, what in the world does knowing that the cookie is 512 bytes do you? You have no idea what data is stored. You don't know if there are 512 bytes of actual data, 128 bytes with lots of fluff, or anything at all other than 512 bytes. Hell, it could be 0 bytes of data and 512 bytes of random data that I submit to every single person that visits the site just to fuck with people like you! You seem like you need something to do ;-)

If the contents of the cookie is a JSON array of recently viewed items, then the size is correlated to whether I've been actively viewing items recently.

Adding random padding makes it harder to get a signal, but with a high enough sample size, it's still possible to get some information. If you always pad to a fixed size, then there's probably no useful information.

At the moment, I think I have enough to do, but I'll probably be looking for something new in the next few weeks. Got any novel single player video game recommendations?

>If

That's are really big word in that sentence. You have NO idea, like 0, what is stored in an encrypted cookie. To even think you do is just pure folly.

This is a very simplistic way of looking at things. A lot of the times in security, having an idea of what's not in there can be almost as valuable as having an idea of what's in there.

I will provide a very simple counterpoint to your argument: say I log in, log out and log in again, dumping my two encrypted session cookies in between. If they are perfectly identical, then knowing nothing else about the environment nor the encryption used, I already know that there's no timestamp value in the cookie acting as a time barrier, nor a challenge-response check, nor a nonce value.

Knowing that, I can focus my attention on stealing session cookies from users for trying replay attacks.

I do have ideas. I can strengthen them by reverse-engineering the behavior using my own account. I participate in follies regularly, so that's not a strong disincentive for me.

The web was designed to be highly interconnected. Deep linking is a feature. Cookies are set via headers. If you load an image from another domain, the headers from that domain could set their own cookies, and your browser will give each domain every cookie it has set.

That is, cookies aren't shared, they're locked down to the domain that set them. It's just that some domains have content loaded by millions of pages. This change won't protect you much if you have a relatively stable IP address without many users on it, because your IP is still in the third party domains logs. This welcome change makes it harder to differentiate people on the same IP, or to track a browser as it changes IPs.

As I'm typing this, I'm remembering how helpful IPv6 is for people who want to track everyone.

If you need Onion Routing then you need Onion Routing. IPv6 Privacy Addressing gives you roughly the same properties you had with IPv4 NAT except now when you did want a stable address you've got one.

Multi address is much healthier in IPv6, so it's reasonable for your browser to even spin up an address associated with a Porn tab, and then destroy it again when you close that tab, while still using your other IPv6 address for a post you make meanwhile to Hacker News. It's also reasonable (while it was often likely to cause mysterious problems in IPv4) to give your local web server a long-lived IPv6 address while your web browser's address changes every hour.

Hmm... I think IPv6 might be actually better. Apple for example will generate and use a temporary IPv6 which changes every few hours to protect your privacy.

Can't one look at the first parts of an IPv6 and roughly know anyway who it is? I've read that one can only control the last parts of ones IPv6 space -- the first, one gets from ones ISP?, can they be enough to know who one is?

Cookies first appeared in Netscape on Oct 13, 1994 [1]. In 1994 the 'web' was a very different place and the current environment of web tracking and invasive advertising companies simply did not exist. And no one saw the privacy invading potential at the time.

[1] https://en.wikipedia.org/wiki/Browser_cookie#History

> And no one saw the privacy invading potential at the time.

Maybe not the privacy invasion potential but ... As we got started building amzn in the fall of 94, it was a no-brainer decision to not use cookies even though they were just arriving. The controversy around the idea was intense and it was far from clear that they would be a success as a technology. It is likely true that there was more attention being paid to the "what? it lets a remote server create a file on my driver?" angle than the privacy one.

How did you manage session information without using cookies?

   http://yourdomain.com/path/to/something?SESSION=af2828c119ae1

and yes, all URLs in every page were rewritten during page generation to include the session ID.

Didn't that break bookmarks?

Sometimes, but usually not. What it did enable was people accidentally leaking their sessions when sharing links.

What did the company do then? (When their users started accidentally leaking session IDs)

(Hmm but you're a different person :-))

This was 1994. Web technology was barely even emergent.

Yes, but someone here quoted an RFC showing that while people may not have understood this in 1994 they did in 1997. And now 25 years later the privacy issue was fixed.

the web was directly bolted on top of the classic client-server network model. there was no concept of a website, just a bunch of requests needed to render whatever the markup (and the dynamic scripting stuff) wanted.

the interaction of those is completely left as an exercise to the (standards) readers. initially only remote code execution was a problem (eg. cross-site scripting), then the usual cross-site request forgery problems. and sure, there was all the usual gimmicks with list of sites you probably visited because it was possible to fingerprint by CSS plus exploiting cache timings.

initially framesets were all the jazz. you got free hosting and the provider just put your stuff inside a FRAME and the ad went above in a different frame.

serious sites had money to pay for hosting and SSL certs. and even if someone stole some credit card numbers the solution was easy, just use paypal!

privacy was seen as something to think about only when someone asked you a/s/l (age, sex, location), so basically when interacting with other humans in chat rooms (or on forums).

...

of course slowly but surely software (more exactly the Internet) is eating the world. being online is the default. Alphabet, the 8th on the Fortune 500 list doesn't even have brick and mortar stores (oh well, there's one in NYC and during this year's Google I/O they announced the second, also in NYC).

Cookies were invented at Netscape like 25 years ago, nobody considered the current situation.

Yes they did. It was foreseen, look at the sibling comment where the issue was discussed in the spec. They just punted, just like they did with https and CAs. (And Javascript, for that matter, although that's less directly security-related.)

The concern was being first to market, not with solid engineering.

The cookie jar was already partitioned by domain. It's non-obvious that the correct design is to partition it by 2 domains (the domain in the HTTP request and the domain in the URL bar).

While I'm not a friend of tracking via cookies nor tracking in general there is some utility there. For example SSO may be done over cookies, like oauth iirc. I don't know of many other use cases though that couldn't be contained with header etc.

Why didn’t cars have safety belts in the first place?