226

What processes and systems are in place so that Google is not able to copy the data on my computer? None. Google Chrome usually runs with the permissions of your user account. The application can then read and modify local files to the same extent your user account can. (These permissions apply to most of the programs you're using.) So you need to trust ...


104

No, that's impossible, unless you change the definition of a file. A file is arbitrary data. Arbitrary data can be encrypted data. Even if we only allow structured data, structured data can - if we assume no space constraints - be abused to store all arbitrary data* (citation needed). Which brings us to the starting point. You can have partial success, ...


96

Read-only file systems can by definition not be written to (At least not digitally. What you do with a hole puncher and a neodymium magnet is your own business). Examples: Live CDs, from which you can boot into an operating system which will look the same on every boot. WORM (Write Once Read Many) devices, used for example by financial institutions which ...


85

A piece of unsandboxed software running on a PC/Mac has (generally) the same privileges as the user running it and therefore can access any data that can be accessed by the user. You are trusting Google (and any other software vendor whose code you execute) not to do anything malicious with that access. If you don't trust Google, your only option as a ...


80

There's an even easier way to bypass the "execute" permission: copy the program into a directory you own and set the "execute" bit. The "execute" permission isn't a security measure. Security is provided at a lower level, with the operating system restricting specific actions. This is done because, on many Unix-like systems (especially in the days of ...


38

If you are running a Linux distribution with SELinux, it is possible to have an additional layer of security. SELinux is an OS-level technology which allows tight restrictions on what processes — like your browser process — can access. In fact, in Fedora and in Red Hat Enterprise Linux (disclaimer: I work for Red Hat, on Fedora!), there is a light ...


35

How secure is the data in a encrypted NTFS folder on Windows (XP, 7)? What is EFS? Folders on NTFS are encrypted with a specialized subset of NTFS called Encrypting File System(EFS). EFS is a file level encryption within NTFS. The folder is actually a specialized type of file which applies the same key to all files within the folder. NTFS on disk format 3....


35

I think you will want more of a philosophical answer than a technical one, given what you are rejecting. A file is just a discrete collection of bits. Relevance and meaning are overlaid onto those bits by a human, but ultimately, it's just bits. How would it be possible to determine if the bits you have are in the same sequence in some unknown previous ...


29

File extensions The file extension actually has absolutely nothing to do with the data in the file or how that data is structured. Windows likes to make you think the extension is somehow magical - it's not, it's just part of the file name, and tells Windows which program to launch when you open the file. (Linux/Android and MacOS/iOS still use file ...


29

Loads of file systems don't have native file system level encryption support. Software-encrypted files can be stored on any file system though, just like any other file. The file system cannot tell the difference between random data and encrypted data. Is there a way to permanently disable any sort of encryption at the OS level? Not so long as code can ...


26

You can set the execute bit, but not the read bit, on an executable file. That way, noone will be able to copy the file, but people can execute it anyway. This is quite pointless today, because a) it works for compiled programs only, not with scripts (on most systems); b) these days, with 90% of all unixes being linux, people can copy executables from just ...


23

Lawyers. You have a contract with Google stating what they will do / you allow them to do. This is called the Google Chrome Terms of Service . And obviously, you have carefully read it before installing it. This includes¹ excerpts like this (emphasis by me): By default, usage statistics and crash reports are sent to Google (…). Usage statistics contain ...


22

First of all (just to be on the safe side) verify the file isn't in the Recycle Bin. If it is, choose Restore and of course shred the recovered file (or maybe you can shred it while inside the Recycle Bin). If the file has been "truly deleted", recover it using an undelete tool such as Piriform's Recuva, then shred it for good. Note (suggested by Chris H): ...


21

Imagine you're on a desert island and I hand you a print out of the US constitution, claiming that it is an exact copy (no words changed). With nothing to compare it against, you have no way to verify that, right? As @schroeder says, a digital file (and its metadata) is just a collection of bits. How do you determine if the bits you have in front of you are ...


18

What processes and systems are in place so that Google is not able to copy the data on my computer? There's not anything in place that makes it so they can't but there's something in place that makes it unlikely that they would: trust. Google's product is you. They want to know everything about you and be able to predict every single decision that you will ...


16

See SSD (Flash Memory) security when data is encrypted in place and watch the discussion links on hard drives. On older drives, it was likely possible to recover overwritten data. The density of modern drives for the past 5+ (and the plus may be 10, 15, or more) years has been so high that a single pass of random data means whatever was there before is just ...


15

1 should not present any danger as long as the file is just saved somewhere and no attempts to open it with anything are made. If you view it even with a text editor, there's already a small danger of exploits. In the case of 2 there are vulnerabilities and exploits, so there are dangers. Some examples of such possible scenarios: Arbitrary file writes ...


13

First a bit of background; Truecrypt uses a classic 2-stage approach: There is a small volume header, which the end user can decrypt with his password. Inside this header there is a master encryption key, which is the one Truecrypt uses to encrypt and decrypt the main user data volume. So your task right now is to recover or re-create the original volume ...


13

The problem with deleting files is that the file data is just one small part of what really gets saved onto your disk. On a modern filesystem there will be lots of metadata and other artifacts scattered around the disk: Journal entries on journaling filesystems, e.g. NTFS, ext3, ext4. Search index entries. Prefetch / superfetch cache entries. Shadow copies. ...


13

The right way to "wipe out" data is to use encryption: never let unencrypted data ever hit the disk. If you do that, then destroying the decryption key is sufficient to destroy the data. The decryption key is small and in many case you can keep it in RAM only (e.g. you type it upon boot, as a "password", which really means "a key that a human remembers"); if ...


12

There seems to be a misconception between encryption and file systems. The two are independent, one can do encryption without having a file system, and one can have a file system without doing encryption. For instance, traditional FAT16/FAT32 file systems do not "support" native encryption like NTFS does with it's EFS sub component. That doesn't mean ...


11

how can a bad guy recover data that's been overwritten just once, since it would change the reflective or height of the gap? There are three basic methods: multiple copies, error correction, and enhanced detection. A hard disk, or CD-ROM for that matter contains a filesystem. A filesystem is an organization of files in a way that makes sense to the ...


10

Forgive me, but the #1 solution for a real-time dependent system is to not let undesignated junk run on it. Users shouldn't be browsing the Internet with an RTOS setup. That needs to stop yesterday. At least in good theory, Deep Freeze type systems will protect your computer from any permanent modification. They intercept all write activity and remap it. ...


10

dir /R shows them in a command-line environment. Microsoft Windows [Version 6.1.7600] Copyright (c) 2009 Microsoft Corporation. All rights reserved. C:\Windows\system32>dir /? Displays a list of files and subdirectories in a directory. DIR [drive:][path][filename] [/A[[:]attributes]] [/B] [/C] [/D] [/L] [/N] [/O[[:]sortorder]] [/P] [/Q] [/R] [/S] [/...


10

NTFS sort of does if you include The Encrypting File System as part of it. The Encrypting File System (EFS) on Microsoft Windows is a feature introduced in version 3.0 of NTFS Secure deletion is supported by cipher.exe: You can use the Windows Cipher utility (with the /W option) to wipe free space including that which still contains deleted plaintext ...


10

YES, the files are recoverable even when they are moved or deleted from the disks. Let's begin with how OS places files in the hard disks. Files are saved on the hard disk in small chunks. These chunks may be scattered all over, rather being placed in contiguous manner. Your File Manger of the Operating System keeps track of the files by knowing the ...


8

You are correct, in order for a file to be deleted the actual disk blocks it previously inhabited must be overwritten. This is generally done with random data; for example, the Windows tool 'cipher' overwrites unused (e.g., formerly used) disk space with 0s, then 1s, and then random data. If a forensic investigator were to look at your computer's disk, and ...


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