Q5sys wrote:RandSec
Is there any reason you are opting to go with DVD media over another form of removable media?
I think so, yes.
It may or may not help to give some of my background, and there is a lot on my site:
http://www.ciphersbyritter.com
I am basically retired, but even 10 years ago I was C programming as a consultant on embedded systems. For the past couple of decades I have been concentrating on security, first cryptography, and now malware. See my various malware articles at:
http://www.ciphersbyritter.com/COMPSEC/COMPSEC.HTM
Recently I have tried to advise the US Government on Bots:
http://www.nist.gov/itl/upload/Ritter_A ... N-BOTS.pdf
so basically I have some background in this area.
With respect to vulnerable store, the issue is less one of "removable" than it is "writable." Both hard drives and USB flash drives are instantaneously writable. Even in Puppy, these systems involve constant interaction with non-volatile store. In particular, it is common in these systems to access and rewrite disk "sectors," which are tiny fragments of files. These are easily read, modified for infection, and written, all in a fraction of a second. The infection process thus is just one more tiny flash of the activity LED among millions. The failure of indication is the failure of the last line of defense, because there are no tools which guarantee to find a hiding malware infection. Absent non-existent OS support, identifying all code which does bad things is theoretically impossible.
In contrast, a Puppy DVD-load system runs in RAM and DOES NOT ACCESS THE DVD in normal operation. Any malware actions to write the DVD thus become apparent and revealed simply by DVD activity. Since there are no DVD "sectors," infection apparently requires a very substantial effort to create a new DVD "session" (a new directory) on the DVD. And even malware cannot write to a DVD which is not in the slot.
Q5sys wrote:I dont get what security benefit you are getting against 'malware' using a dvd. If you are burning save sessions to a new DVD, then you're not using a read only system... so you are still open to infections.
I guess I would say the difference is that your model of "read-only" vs. "writable" is too simple to capture the reality of the situation. This is, of course, similar to the model of the file system being protected by permission bits, when malware interprets those bits. It is also similar to the model of running as root, when the system is for just a single user anyway. The simple models often are imperfect substitutes for deeper understanding, and we often need to get beyond them.
There is, and can be, no perfect security. All security comparisons are necessarily relative. The usual disk-install Puppy system has a continuous interaction with the hard drive (or USB flash), with continued drive activity flashes, just like Microsoft Windows, and is similarly vulnerable. Malware infection of an intensely-used and easily-writable drive is just one tiny blip among many, which is no indication at all. In contrast, a Puppy DVD-load system has a quiet and dark DVD writer; attempted malware infection lights up what should be dark and so is obvious.
On the other hand, if Puppy would treat a USB flash drive similar to the way it treats a DVD, then we would have something! It would be a much faster load, and THEN WE WOULD REMOVE THE USB! I particularly would appreciate the DVD Save ability to keep multiple versions of files (in different directories), allowing one to go back to earlier article versions. That is what we could have, but it is not what we do have. We are necessarily forced to deal with what we have.
Q5sys wrote:Is there any benefit you are gaining? Because it seems like you are dealing with a ton of headaches because of it.
First of all, I am unsure about this "ton of headaches" meme with respect to DVD-load operation. That certainly was true when I first started with Puppy, now several years ago, and it was very frustrating until I understood some of the problems and found solutions. Fortunately, all operations necessary to make DVD-load a practical mode are in fact available. These are not hard, or "headaches," just hidden. I use it all day, every day.
The benefit is to (*almost* absolutely) prevent infection, which simply cannot be done otherwise in current systems. Even Microsoft Windows 8, which supports or demands UEFI, seems unlikely to address the real problem. A correct response does not need signing or cryptography. The problem is that the current concept of "disk drive" does not include a protected area for the OS, which means that anything which can write to the disk (having first "owned" the OS), at least potentially can infect ALL FUTURE SESSIONS. We seek to prevent this *infection*.
It is important to distinguish *infection* from malware execution: Malware can *run* whenever it somehow gets through the "front end" protections, like router firewall, software firewall, browser, browser security add-on's, etc., or trojan email attachments, or infected USB flash, etc. Because the Web and our equipment was not designed to prevent malware from running, it may run, even in Linux. But "running" is not "infection."
*Infection* is whatever process brings the malware back for session after session. In Microsoft Windows systems, which are universally hard-drive based, malware adds or modifies something on the drive. A decade ago and more, malware would just drop some new files into the startup folder. Nowadays, malware may modify actual machine code in existing files, and then prevent normal file commands from seeing changes. In any case, something changes in start-up storage which somehow starts the malware.
The chances of running into malware in a normal browsing session, at least when actively avoiding danger, are small. The reason malware is an increasing problem is the *infection*, not the malware per se. If *infection* can be defeated, we can change malware from running during each full future session, to just the remaining session from the first encounter.
Puppy has an important and unique, yet unappreciated, facility. Merely by doing a DVD re-boot before online banking (or online investment, or online purchasing), any running malware can be ended. That is not the case for any hard-drive system.
And while many other "LiveDVD" systems exist, the ability to load the complete system into RAM, and thus remove the DVD and along with it even a slight DVD vulnerability, is rare.
But the really unique part is that DVD-load Puppy can do security updates to the existing programs without waiting perhaps months for somebody else. This is different from a hard-drive or USB update in that, if we do a reboot immediately before updating online and then a Save, we are quite unlikely to have malware running. We have no such assurance with a hard drive or USB flash system.