4 Replies Latest reply: Feb 15, 2007 1:24 AM by Thomas.Leplus
Thomas.Leplus Level 1 (0 points)
Hi everyone,

I am installing an airport extreme 802.11n base station in my office and I need to keep the same WEP key as my previous access point. The format of the key is 26 hexadecimal digits.

In the setup utility I tried to prefix the digits with a dollar sign but I doesn't seem to work with the new model (it keeps saying that I can only use 13 characters). I also tried to convert the key to ASCII but it is still rejected (probably because of the weird ASCII characters).

Any suggestions?



Airport Extreme (MA073Z/A), Other OS
  • William Wert Level 1 (25 points)
    Hi Thomas. I am pretty sure that wep is not compatible with the n spec. Dont know where I read that, but wpa works fine on it.

  • iFelix Level 8 (35,145 points)
    One of the problems with WEP is that the actual standard relies on a 10 character HEX key for 40bit WEP and a 26 character HEX key for 128bit WEP.

    In order to make things easier for people, vendors use certain algorithms to convert simple alphanumeric passwords (or passphrases) into HEX keys, thus enabling people to use simple memorable WEP password rather than lengthy HEX keys.

    The problem is that different vendors use different algorithms to generate the HEX key and therefore a ASCII password on an AEBS will be hashed differently on a Netgear client and vice versa.

    One thing is a 13 character 128 bit WEP password will be hashed by all vendors in the same way (if you use 40bit WEP then a 5 character password is required).

    Though sometimes not even that works and the HEX key must be used regardless.

    AirPort: Joining an encrypted wireless network

    Choosing a password for networks that use Wired Equivalent Privacy (WEP)


    "WPA Personal" on the Mac corresponds to plain WPA, with a pre-shared key (PSK) and TKIP encryption, on non-Apple wireless routers. The same alphanumeric password should work on both.
  • Thomas.Leplus Level 1 (0 points)
    Hi Bill,

    Maybe the WEP key will prevent the users to reach n speed but I have no other choice. I need to keep the same WEP key as we have many employees and contractors that come in the office occasionally and use the wifi. Sadly I have to maintain backward compatibiliy for their laptops that do not all support WPA.


  • Thomas.Leplus Level 1 (0 points)
    Hi iFelix,

    The thing I don't understand is why the Airport Utility don't accept an hex key directly to prevent any uncertainty on how the hashing is done.

    I understand that forcing the user to choose a plain text key of 13 charaters will make sure that the key is compatible with most clients. But this also makes the key weaker on an already weak encryption scheme.

    The dollar sign trick was a great feature for advanced users who want to choose an hex key. And it is so easy to implement that I don't see why they removed it.

    Hopefully someone will come up with a way to do that.