and that's the problem, on a modem only one machine can attack you at a time, on the internet millions can have a go at once. the flexibility argument also cuts both ways...
I agree completely. However, at the end, if the customer (owner) doesn't want the product (the ATM), the ATM company goes out of business.
So, what you're saying is that dialup connected machines have the facility to receive calls, but internet connected machines only do outgoing connections? that seems odd. It would be just as easy to secure a dialup machine by simply telling it not to answer the phone. I have to believe that if the dialup machine is set to answer phone calls, the internet connected machine will be set to receive some form of incoming connection as well. otherwise it's not the communication medium that is adding the security, but the decision on whether or not to accept incoming communications.
OK, with regard to the ability to accept incoming communications, it's about customer convienence. With a machine connected through a standard phone line, 99% of the machine's I've installed get to share their phone line with the location's fax line. If the ATM is dialing out at set intervals, it is taking both the machine and the phone line out of service for 45 seconds to a minute every time it goes out. That's bad for business. The solution used to be (5 or so years ago) that the processor would call the ATM twice or so a day to check on it's health status, etc.
Also, remember, most of my customers have this feature disabled.
Now, however, with an IP based connection, the information transfer is instantaneous (or nearly so, as viewed by the customer). Therefore, it's not a big deal for the machine to contact the processor every 15 minutes or so with a status update. Therefore, as there is no need to remotely access the machine, they simply removed the functionality.
In fact arguably the TCP/IP connection is still less secure than a similarly configured dialup connection due to increased chance of various MITM attacks, IP or DNS spoofing attacks, or simple protocol vulnerabilities in the OS that get found/exploited by the millions of bots that can be brought to bear on attacking a machine over the internet
This is a fair point. However, the data that you're capturing with all of these attacks is super encrypted (not in the "super! thanks for asking" sense, but more in the they encrypt data that has already been encrypted using a different process), a MITM attack is going to log a bunch of gibberish packets. Assuming you can break the one time key established in handshake, you can't break the secure keys that are only known at the source and destination.
The "white label" ATMs I've worked with have never required me to do more than supply a phone jack, so you may be right about them using consumer grade ADSL connections.
In every bar/gas station/liquor store/bowling alley/porn store I've ever worked on an internet connected machine, it's jacked into a consumer ADSL or Cable connection. I've yet to see a dedicated connection for the ATM. That's part of the value proposition for the owner, he gets to eliminate a $75 a month phone line from his overhead by putting the machine online.
The only differences are cost of the connection itself (so you may be right about it being prohibitive) and some routing at the server end, however the big banks are already set up for that sort of stuff, so it shouldn't be much effort to do it for the white labels as well.
When I said cost prohibitive, I was indeed talking about the cost of the connection. You work for a telco, so let's be charitable. What do you figure a setup like this costs? $250 or $300 a month? For a machine that only costs $3000 and only makes the owner $300 a month? What's his business justification for that purchase? There's no way he's going to pay that.
Like everything else in business, these little guys are 100% focused on the bottom line. They want to use that ATM to make money. Period. If the costs of keeping it going exceed the return, they're going to get out of it.