By Kurt Seifried (kurt@seifried.org)
There are a number of pros, cons and alternatives to port knocking.
2006 11 30
{ Monthly Archives }
November 2006
2006 11 27
Port Knocking 101 - The Basics
By Kurt Seifried (kurt@seifried.org)
Port knocking is defined as:
In computing, port knocking is a method of externally opening ports on a firewall by generating a connection attempt on a set of prespecified closed ports. Once a correct sequence of connection attempts is received the firewall rules are dynamically modified to allow the host which sent the connection attempts to connect over specified port(s). [1]
2006 11 23
February 18, 2008 - Death of the Analog Cell Phone Network
By Kurt Seifried (kurt@seifried.org)
February 18, 2008 - Why does this date matter? Because that is the day that the Analog Cellular network is supposed to be turned off in the U.S.A., completing the switch to digital networks such as GSM.
So what? Unless you’re still living in the cell phone dark ages you probably have a digital cell phone. Or do you?
2006 11 20
Privacy Laws - A Threat To U.S. Financial Services Corporations?
By Kurt Seifried (kurt@seifried.org)
There is a new and potentially damaging problem on the horizon for many financial service firms, ranging from banks to mortgage lenders and insurance companies.
Privacy laws designed to protect consumer.
Now don’t get me wrong, I generally support the idea of laws that will provide protection to consumers with respect to their personal data (i.e. name, social insurance number, banking details, address, etc.) but I can see some very serious potential problems because of the way US state laws interact with corporations.
2006 11 16
The end of mechanical locks?
By Kurt Seifried (kurt@seifried.org)
Traditionally physical security has been addressed primarily by mechanical locks to control access to places, be they buildings or a specific room. A business would have mechanical locks on all external doors and many internal doors, and these would typically be locked when no-one is around (e.g. at night). Combined with a decent alarm system the mechanical locks would slow an intruder down long enough for them to be detected and for the police to respond in most cases. For areas without an alarm system the locks would ideally discourage the attacker, there is a big difference between kicking in a door and simply turning the knob to see if it’s open.
For centuries (indeed in some areas millennia) this balance held, mechanical locks were effective in discouraging attackers or slowing them down enough to be effective. However a new lock picking technique has changed the balance, potentially rendering most mechanical locks useless.
2006 11 14
Miniature Computers That Can Break Your Network Wide Open
By Kurt Seifried (kurt@seifried.org)
One aspect of information security that is often under looked is physical security. While attention is often paid to secure areas containing servers, network equipment and telecommunication gear not as much attention has been paid to the fringes of the network. Although some security standards such as 802.1x and various network access control (NAC) products exist that can be used to address the network fringe they all contain one major weakness.
Assuming a network has implemented end to end security in the form of 802.1x or a network access control (NAC) solution they all make one major assumption: that a man in the middle attack can’t be executed once the end point has authenticated. For example 802.1x addresses this directly, if the network port detects that the connection is dropped it requires the end point to re-authenticate before it’s allowed to have network access again. If the network hasn’t implemented such a scheme then it becomes trivial to execute a man in the middle attack by physically inserting another computer in between the network equipment and the end machine.
But that would be pretty obvious wouldn’t it? I mean you think a user (even the dullest one) would notice a second machine plugged into their network drop, with their computer daisy chained off of it.
Maybe. Maybe not.
2006 11 09
Why User Education Will Never Work
By Kurt Seifried (kurt@seifried.org)
Just so we’re clear I’m using the word work in this context (from Dictionary.com):
19. to act or operate effectively: The pump will not work. The plan works.
In this context I think it’s quite clear that user education will never work. Of course saying this is tantamount to heresy for many people, but we also used to think the world was flat.