Using gpg to encrypt files on a web server

I was working on my website, and I wanted a way to protect files that are uploaded by the users. My solution is to encrypt the files with gpg when they are uploaded. Only the public key is stored on the server and the files are encrypted with this. The only way for the files to be decrypted is for them to be downloaded and then decrypted with my private key.

The steps needed in order to achieve this are:

  1. Obtain gpg and generate a public/private key if you don’t already have one (gpg –gen-key)
  2. Export your public key to a file (gpg -a –export > pubkey.txt)
  3. Upload the pubkey.txt file to your server
  4. Create a directory accessible to the webserver (apache) process
  5. Create a public keyring in this directory (gpg –no-default-keyring –keyring /path/to/pubring.gpg –import pubkey.txt)
  6. Make sure that this file is readable by your webserver process
  7. You may now encrypt files using the command line “gpg -q –batch –no-options –no-default-keyring –keyring /path/to/pubring.gpg -r brett –always-trust –output encrypted.enc –encrypt unencrypted.txt”.

Make sure you back up your private keyring – if you lose it, your files will NEVER be decrypted!

Mobile Reading

I’ve been interested in electronic book readers with e-Ink technology ever since I read about the Sony Reader. I waited and waited for them to bring the reader out in the UK, but it’s been over a year and still no release.

A friend sent me a link the other day about the Iliad. This seems like a fantastic device, but it’s quite expensive!

I then discovered a review on e-book readers on Wired magazine. This led me to discover Bookeen’s CyBook Gen3. The CyBook is lighter and cheaper than the Iliad and the battery lasts a lot longer. According to two reviews I read; the screen quality isn’t quite as good on the CyBook as compared to the Iliad, and both reviews mentioned that the button for turning the pages was awkwardly placed. There seems to be a very active developer community for the Iliad which is a big plus.

The price, weight and power consumption difference between the Iliad and the CyBook are probably because the Iliad has a Wacom digitizer in it, so you can draw and take notes on the screen. Also the Iliad screen is bigger and supports 16 shades of gray as opposed to 4.