encryption

REINER SCT cyberJack RFID komfort

Dec 212011

The REINER SCT cyberJack RFID komfort is a smartcard and RFID card reader popular in Germany as it supports the German identity card and its RFID technology. Here are my notes on the device, some tweaks and how to use it.

Current problems

As of 2011-12-28 I’m having a couple of problems with the device:

The electronic money system Geldkarte does not work right now as this needs the SECODER certification which will take some more months.
OpenSC seems not to work with this card reader
The OWOK loginCard that came with the device is almost useless:
- winlogin does not work with that card

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Transparently Encrypt Folders with encfs

Mac OS X 10.7 Lion No Responses »

Dec 142011

EncFS (on Wikipedia) – a FUSE filesystem – can help encrypt cloud synced folders (using business proof AES or Blowfish algorithms). It operates on smaller blocks (not a single big file) and thus works well with Dropbox, because when only one decrypted file is changed, it won’t upload your whole Dropbox again.

Prerequisits / Installation

Install Fuse4X and install EncFS. If you have Homebrew, this is as easy as:

brew install encfs

Setting Up The Encrypted Dropbox Folder

We don’t want to encrypt the entire Dropbox as we would loose other dropbox features as sharing some files via a public link etc. So we set up an encrypted Dropbox subfolder:

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Sketch of an Advanced HDD / Partition Setup with high availability (mdadm software raid), encryption (dm-crypt) and high flexibility (lvm volume management)

Ubuntu 10.10 No Responses »

Feb 282011

Recently I found an interesting comment on an article about Fedora 16 maybe using btrfs as default file system: The author Vanger explained his current hard disk / partiton setup on a server and how he hopes to get a more efficient system with btrfs. More than the outlook at the btrfs future I was stunned by his current setup that I try to present in this image:

He combined mdadm, dm-crypt and lvs to have a server system with the following properties:

high availability by the use of a redundant array of disks (raid)

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Sketch of an Advanced HDD / Partition Setup with high availability (mdadm software raid), encryption (dm-crypt) and high flexibility (lvm volume management)

Setup and Using GPG (GnuPG)

Ubuntu 8.10 No Responses »

Feb 182009

http://www.madboa.com/geek/gpg-quickstart/
https://help.ubuntu.com/community/GnuPrivacyGuardHowto
for further information see http://www.gnupg.org/documentation/
for e.g.: http://www.gnupg.de/gph/en/manual.html

Import a key from somebody else using a textfile

gpg --import key.asc

Check fingerprint

List all imported keys with their fingerprints:

gpg --fingerprint

Sign someones public key

To accept other’s messages as authentic you have to sign them (for example when getting the message “There is no assurance this key belongs to the named user”):

gpg --sign-key <user-id>
# <user-id> might be the id of the key:
gpg --sign-key 4CD35F64

Building the web of trust – update signed keys of others on the keyserver and

gpg --keyserver wwwkeys.pgp.net --send-key 4CD35F64
# or send all keys to the keyserver:
gpg --keyserver wwwkeys.pgp.net --send-keys

To specify how much you trust the signing decisions of others, run from time to time:

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