Bugtraq mailing list archives
Re: otp - the next generation
From: Gregory Steuck <greg () NEST CX>
Date: Thu, 22 Mar 2001 15:46:44 -0800
"Lukasz" == Lukasz Luzar <lluzar () DEVELOPERS OF PL> writes:
Lukasz> The system is the most reliable way of
Lukasz> secure authorization. It eliminates all disadvantages of a
Lukasz> typical login/password and any other otp implementations.
These claims are questionable.
Lukasz> When you want to log into the server from an untrusted
Lukasz> network, then you send a SMS message with your real login
Lukasz> and password (e.g. "john 12blah45") in the body of message
Lukasz> to the GSM phone connected to the server. When the server
Lukasz> receive a message, the smsotpd daemon process the request in
Lukasz> the following steps: 1.Checks if the user is permitted to
Lukasz> authorize from the phone number (checks /etc/smsotp.access
Lukasz> file),
This is the part the whole authentication mechanism depends on. You made
at least 2 assumptions here:
1) GSM phone network is secure between the endpoints (phones) and can
not be sniffed.
2) SMS source address can not be forged.
I am pretty sure that both assumptions are wrong. Phone company (or
companies, I don't know how the messages are routed) will most certainly
be able to sniff your messages and forge the source address.
So, what you are proposing boils down to replacing an open network (the
Internet) with some closed phone company network. I don't trust my phone
company any more than my ISP. Do you?
Thanks
Greg
Current thread:
- otp - the next generation Lukasz Luzar (Mar 22)
- Re: otp - the next generation Szilveszter Adam (Mar 23)
- Re: otp - the next generation Casper Dik (Mar 23)
- Re: otp - the next generation Denis A. Doroshenko (Mar 23)
- Re: otp - the next generation Gregory Steuck (Mar 23)
- Re: otp - the next generation Tollef Fog Heen (Mar 23)
- Re: otp - the next generation Ben Laurie (Mar 23)
- Re: otp - the next generation Dag-Erling Smorgrav (Mar 23)
- Re: otp - the next generation Tristam Fenton-May (Mar 23)
- <Possible follow-ups>
- Re: otp - the next generation Elias Levy (Mar 23)
- Re: otp - the next generation Szilveszter Adam (Mar 23)
