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Discussion of features in Mozilla Firefox
Tularis
 
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Post Posted July 20th, 2010, 6:03 am

Hello,

I have firefox set to "Always start Firefox in a private browsing session", but when I go to "About:Cache" I can see:

Memory cache device

Number of entries: 39
Maximum storage size: 27648 KiB
Storage in use: 363 KiB
Inactive storage: 363 KiB

I would assume that this is stored in RAM and not on the Hard Disk?
and then it "Should" be deleted when the browser is closed?

Is there any way to prevent "ALL" Caching?

Bluefang

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Post Posted July 20th, 2010, 12:09 pm

The memory cache is used for decoding and decompressing images and other media. It shouldn't be disabled. Yes, it will be deleted when the application closes (memory is only used while the program is running).
There have always been ghosts in the machine... random segments of code that have grouped together to form unexpected protocols. Unanticipated, these free radicals engender questions of free will, creativity, and even the nature of what we might call the soul...

Tularis
 
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Post Posted July 20th, 2010, 12:23 pm

Ok but.

Is it possible for it to be disabled? If so how?

Since the main stream of broadband internet I have found the "Cache" of any browser a rather useless feature, Would it be possible to have a browser not cache anything? Or if you were worried about complete privacy have it store what it needs to in an encrypted memory space.

Just some wonderings...

Bluefang

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Post Posted July 20th, 2010, 1:15 pm

Being a little paranoid, are we? For the record, it's probably a bigger privacy risk to re-download content every time you want to view it rather than caching it. It's also a waste of bandwidth. Also, the memory cache is not a privacy risk because it disappears when Firefox does.

Actually, I was a bit incorrect in my last post. The memory Cache Device is just a normal content cache (I think), and it's controlled by the browser.cache.memory.* settings.

The image and media caches are used for decoding and buffering media played natively in the browser. THESE SHOULD NOT BE DISABLED. Disabling them will likely cause performance problems. For image.cache.size and media.cache_size, see here:
viewtopic.php?p=7096305
There have always been ghosts in the machine... random segments of code that have grouped together to form unexpected protocols. Unanticipated, these free radicals engender questions of free will, creativity, and even the nature of what we might call the soul...

Tularis
 
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Post Posted July 20th, 2010, 1:42 pm

hmmm, no I'm not paranoid. I've just been wondering on this for a while.
Seeing as all the browser market their new "Privacy" feature I would have thought someone would have developed an entire browser (possibly based of Firefox) that doesn't and couldn't cache anything at all. (I know there is Tor and such, but that doesn't stop the problem)

As for the "Waste of bandwidth" I personally wouldn't care and I think others wouldn't too.

But if caching was necessary could you get around it with an encrypted cache where the key was only based on that session?

like I said before Just some things I've wondered about.

Bluefang

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Post Posted July 20th, 2010, 1:58 pm

As for the "Waste of bandwidth" I personally wouldn't care and I think others wouldn't too.

Even ISPs with 'unlimited bandwidth' plans have a bandwidth cap, even if they don't trell you about it.

Also, caching is used for other thing as well, such as backwards/forewords history navigation, undo closed tabs, and probably other stuff. Other caches (image/media) are used for page rendering and buffering, and don't really have anything to do with content caching.

Private browsing is about not leaving any traces behind. That doesn't mean the browser doesn't cache things or cripples its self. It just means that it's expected to clean up after its self. That why the disk cache isn't used; it's not guaranteed to be cleaned up (i.e. if there is a crash).

If anything, the biggest breach in private browsing is plugins. For example, Flash caches its own content and stores its own cookies (though this was supposedly addressed in 10.1).
There have always been ghosts in the machine... random segments of code that have grouped together to form unexpected protocols. Unanticipated, these free radicals engender questions of free will, creativity, and even the nature of what we might call the soul...

Tularis
 
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Post Posted July 20th, 2010, 3:30 pm

Indeed, I completely agree. I have noticed the flash issues, mainly with videos and FLA files etc..

Well perhaps the first person / company to offer a secured browser where all necessary caching was encrypted including plugins (god knows how :P)
would be quite successful in the privacy market. I think it would be quite interesting to see someone attempt it.

All the ISP that I have used / seen that have an unlimited plan (In the UK) wont CAP you at all, but they do normally limit your speeds in peek hrs regardless of how much bandwidth you have / are using.

Bluefang

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Post Posted July 20th, 2010, 6:00 pm

... where all necessary caching was encrypted including plugins.

Why is this necessary? If you have snooping around in your RAM/VM then you have far bigger problems.

All the ISP that I have used / seen that have an unlimited plan (In the UK) wont CAP you at all, but they do normally limit your speeds in peek hrs regardless of how much bandwidth you have / are using.

My Comcast 'unlimited' plan has a 250GB cap, and my Verizon 'unlimited' data plan has a 2GB or 4GB cap. Similar things can be found on almost all US service plans. Granted, regular web browsing won't consume very much. However, watching a lot of streaming video, downloading large images, or using other services like Pandora or BitTorrent can easily add-up fast.

Also, when you purchase online data services (i.e. web hosting), their 'unlimited' plans are also capped (bandwidth and disk) though they rarely tell you what it is until they grump at you.

---

Also, there is something devastatingly important about caching that I forgot to mention. It doesn't have anything to do with you, but the load you place on the web servers and networks. When you download something, that takes resources on the server you're downloading it from and the network you're downloading it through.

Caching is important because it prevents you from re-downloading content that hasn't been changed on the server. Whenever you make unnecessary requests to re-download content, you're consuming resources that could be used to serve other visitors that haven't had the opportunity to download content yet. If you're abusive enough, some servers will actually ban you from connecting and downloading.
There have always been ghosts in the machine... random segments of code that have grouped together to form unexpected protocols. Unanticipated, these free radicals engender questions of free will, creativity, and even the nature of what we might call the soul...

Tularis
 
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Post Posted July 20th, 2010, 11:23 pm

Well I still think it would be an interesting project.

Not sure why your so evasive ;)

Bluefang

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Post Posted July 20th, 2010, 11:43 pm

What am I being evasive about? I simply asked what encrypting the RAM cache would accomplish, and pointed out that cache still plays an important role on the modern web.
There have always been ghosts in the machine... random segments of code that have grouped together to form unexpected protocols. Unanticipated, these free radicals engender questions of free will, creativity, and even the nature of what we might call the soul...

Tularis
 
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Joined: July 20th, 2010, 5:52 am

Post Posted July 21st, 2010, 12:05 am

lol, not to worry.

But I wouldn't be surprised if we saw something like this in the coming years, seeing as how "Privacy" is now the new buzz word around the browser market.
I mean it seems search engineers are now selling themselves with the face that "We don't Record you IP address" so a browser that could "Never store what you do online" could be quite successful.

Bluefang

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Post Posted July 21st, 2010, 12:29 am

Firefox can already do that.

Tools -> Options -> Privacy -> Firefox will: Never remember history -OR- Tools -> Options -> Privacy -> Firefox will: Use custom settings for history -> Permanent private browsing mode

Disabling or encrypting the memory caches really has no privacy gain. If something has the ability to snoop around in an applications memory, your computer is already compromised and any notion of privacy goes out the window. Not to mention there are a whole lot easier methods, to find out what you're doing, than scraping memory.
There have always been ghosts in the machine... random segments of code that have grouped together to form unexpected protocols. Unanticipated, these free radicals engender questions of free will, creativity, and even the nature of what we might call the soul...

anjalip222
 
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Post Posted August 5th, 2010, 10:52 pm

Tularis, there are 2 kinds of Firefox caches - (1) memory cache (in RAM) and (2) the disk cache (in your HDD).

The disk cache you can disable, or shift it to any other secure location you like, or encrypt the cache folder in Windows with the native encrypting file system.

But for memory cache, why do you want it to be encrypted? It's in RAM, so it's secured anyway. The memory cache and its content vanishes everytime you restart the PC.

James
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Post Posted October 2nd, 2015, 2:07 pm

r00tsR0k3r I splitted your post off to be a new thread at viewtopic.php?f=38&t=2965523 as this thread was over five years old. Locking.

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