Canceling File Encryption Windows 7
2014-07
Daniel Valland
I was trying to encrypt a single file, large file container of 100GB.
I clicked on the Properties --> Advanced --> Encrypt contents to secure data. However, realizing that this would not allow for on-the-fly decryption, and given the files large size, I clicked the cancel button to stop the encryption. Now the dialog box simply says: "Processing..." and has done for several hours. Given that it had only been encrypting for a few minutes, I expected a similar time frame to revers the operation. What exactly is it doing? Windows seams notorious for doing operations without stating progress or what it is doing.
smc
Well, I am not experienced enough to state exactly what is your system doing. However from my experience with windows, I can recommend you not to attempt to terminate the process or force PC to shutdown. This _will_result in data corruption. Be patient and wait for reasonable amount of time. Even if it takes over 24 hours. Meanwhile you can try experiment with smaller files on a different machine and try to work out approximate encryption speed per Mb of data. Then use this calculations to estimate the timing for your 100GB file. Also for the worst case scenario multiply this by 2 to get process completed and then reverted and add up to 10% of margin just to be sure.
And be patient
Adam Matan
I want a colleague of mine to send me a sensitive Microsoft Word document via e-mail. Since Word's encryption is questionable, I would like to encrypt the file using a passphrase.
Do you know of any encryption method that a novice user can easily use? I wouldn't like to prompt for keys or anything like this - just provide a simple interface for single file encryption.
David Pearce
Although it might be a bit overkill, TrueCrypt allows you to encrypt files and folders and shows up as a removable device in My Computer. It is free and (in my opinion) user friendly.
Main Features:
Creates a virtual encrypted disk within a file and mounts it as a real disk.
Encrypts an entire partition or storage device such as USB flash drive or hard drive.
Encrypts a partition or drive where Windows is installed (pre-boot authentication).
Encryption is automatic, real-time (on-the-fly) and transparent.
Parallelization and pipelining allow data to be read and written as fast as if the drive was not encrypted.
Provides plausible deniability, in case an adversary forces you to reveal the password:
Hidden volume (steganography) and hidden operating system.
Encryption algorithms: AES-256, Serpent, and Twofish. Mode of operation: XTS.
Pablo
Check out AxCrypt. It's open source and made for encrypting individual files.
KovBal
There are two ways for this.
You can compress your file with some archiver like 7-Zip. They can encrypt the content. However, watch out because older versions of WinZIP for example doesn't use strong encryption. In contrast, 7-Zip uses strong AES encryption and can even encrypt file names.
Or you can use EFS. EFS works on NTFS. It doesn't ask you for a password because it uses your Windows credentials. It's important to know that this way you can't securely transfer your files. Your files are only encrypted on your HDD. If you use an USB flash drive or send a file in e-mail than it won't be encrypted.
Adam Matan
I have solved this using Putty Secure Copy, through a Linux box I have on the net. The user downloaded scp to the same directory where the file was, and I have send him the exact scp command by mail.
Kind of reversed the problem - using encrypted connection rather than encrypting the file. Of course, this solution might not fit everyone's needs - it works only if you have a trustworthy server.
But in second thought, one can always install a virtual machine, set the router to port-forward the ports and ask his novice friend to ssh to the virtual machine... But perhaps that's a rather long shot.
UPDATE
winscp works even better. It has simple and nice GUI that every novice user can handle.
KTC
GPG (and the commercial PGP) have the option to encrypt something symmetrically as well as the more common (for these two applications) asymmetric option. i.e. It let you encrypt something using a passphase, and later decrypt it using that passphase. Either program can decrypt what the other one have encrypted (using the right passphase obviously).
To encrypt a file with symmetric encryption, the syntax is:
gpg --symmetric filename
To encrypt a file so that the encrypted output is in plain text, rather than as a binary file:
gpg --symmetric --armor filename
To decrypt the file:
gpg -d encrypted-filename
Since you probably want your original file back as a file, rather than coming back at you as lots of (binary) text, you'll want to redirect the output to a file:
gpg -d encrypted-filename > filename
Of course, you can use a GUI front end to do all that as well.