Re: Smart card proposal

[Hugo Fortier <hugo.fortier () gmail com>]

USB Flash drive and Credit Card sized CD are't to be compaired with
SmardCard. They have none of the propriety that a smartcard have...
While it's is somewhat better than storing the key directly on the
computer, it should't be considered a lot more secure. And it be a lot
cheaper tu just use a crypto key stored on the PC.

SmartCard readers are getting cheaper and cheaper, only issue is that
inexpensive one does not have PIN Pad included in the reader. It's a
bad idea to enter your pin on your computer keyboard.

I agree with you that PIN number generator are interesting, but for a
online bank they does't provide the advantage a smart card would give
them (Aka Digital Signature).

Also those RSA Token have short lifetime, due to the fact that they
have built-in battery and are easy to break. I doubt RSA Token are
cost effective on big deployment like Online banking...

We have to remember that the cost of the solution have to be lower
than the lost caused by fraud.

Hugo

On Mon, 24 Jan 2005 07:27:54 -0500, Richard M. Smith
<rms () computerbytesman com> wrote:
> Since almost no PCs that I am aware of have SmardCard readers, I don't see
> how this scheme works.  Could a USB flash drive or a credit card-sized CD
> ROM be used instead? (See
> http://www.mediaheaven.co.uk/cd-business-cards.htm)  These devices typically
> don't require new software.
>
> I still like a PIN-number generator device for a key ring as the best method
> to improve security beyond passwords and PINS.  One of these devices
> generates random PIN numbers that are only known by the bank and the person
> who is holding the device.  They are popular her in the States in remote
> access systems to corporate networks.  (See
> http://www.rsasecurity.com/node.asp?id=1173).
>
> Richard
>
> -----Original Message-----
> From: Rogan Dawes [mailto:discard () dawes za net]
> Sent: Wednesday, January 19, 2005 5:47 AM
> To: Webappsec List
> Subject: Smart card proposal
>
> Hi folks,
>
> As part of the discussion recently about phishing, I was thinking about
> how a hardware token (and a smart card in particular) could be used to
> secure web transactions.
>
> It also struck me that more and more banks are issuing credit or debit
> cards with smart-card capabilities.
>
> This led to the thought that banks could use the smart-card capabilities
> (via a smart-card reader) to store a private key and SSL client
> certificate, which would be used to authenticate their clients when they
> wish to perform internet banking.
>
> Positive consequences:
>
> The bank is performing the same effective authentication as they do at
> their ATM's. Something you have (the card) and something you know (the
> PIN). This may or may not be the same PIN as would be used in an ATM.
> This would be a policy decision, made by the issuing bank.
>
> Policy decisions can be enforced on the smart card, because the smart
> card can run applications. So policies such as PIN complexity, lockout,
> etc can all be specified by the bank, and enforced. This is platform
> independent, browser independent, CPU independent, etc.
>
> Users already have an idea of how to protect their credit cards. They
> know what the implications are if they get lost or stolen. They tend to
> keep them in a safe place. Even if they do get compromised, the card is
> still protected by a PIN, and is effectively unusable.
>
> ATM's mostly already have infrastructure to read and communicate with
> smart cards. Users can use ATM's as self-service terminals to set up
> their internet banking. e.g. the user enters their PIN at the ATM,
> selects Internet Banking, Register. The ATM instructs the smart card to
> generate a private key, takes a copy of the public key, generates a CSR,
> requests the Bank's CA to sign the cert, and installs the cert into the
> smart card. It then asks the user to choose a PIN for the certificate,
> so that it cannot be accessed without it. At the same time, it links the
> certificate to the same accounts that the user can access via the ATM,
> so that Internet banking is effectively seamless.
>
> If the user forgets the certificate PIN, and tries to guess it more than
> ${policy} times, the smart card locks it out. Then, the user can go to
> an ATM, enter his ATM PIN, request a certificate PIN reset, the ATM then
> supplies a (card specific) PIN Unlock Key, which allows the user to
> enter a new PIN for the cert.
>
> The certificate lifetime would be the same as the validity period of the
> credit card. When the bank issues a new credit card, the user should go
> back to an ATM, and reregister for Internet banking. Alternatively, if
> the user is already registered, the bank can pregenerate a key and
> certificate in the card, register it with Internet Banking, and provide
> the user with the certificate PIN in the same way as they do with the
> ATM PIN.
>
> Depending on the bank's policy, the user may be able to change the PIN
> at their own computer. This would however mean that the bank would not
> be in a position to know what the current certificate PIN actually is.
> An alternative is to require the PUK before allowing PIN changes. The
> PUK could only be provided by the ATM . . . allowing the bank to obtain
> a copy of the certificate PIN . . .
>
> Negative Implications:
>
> If the credit card is stolen, there is a risk of access via the Internet
> as well. This may or may not already be an issue, if users can
> self-register using their credit card PIN. (possible in some countries)
>
> Using the smart card at a merchant might allow the merchant to issue
> additional internet banking transactions while the card is inserted in
> the slot, and the PIN has been entered into their card processing
> device. I think the close coincidence of the fraudulent transactions
> with a legitimate transaction would be suspicious. Note that it would
> (should) not be possible to delay the transaction until after the card
> is taken out. (Question: If I connect using a client cert, establish a
> SSL shared session key, then remove the smart card, can I continue to
> use that session key?) Also, most merchants do not have access to
> reprogram their card terminals, this is generally done by the supplier.
>
> Session Riding:
>
> One thing that I have ignored up until now is the issue of session
> riding, where an attacker makes use of the fact that the SSL connection
> is transparently created.
>
> One thing mitigating against that is the requirement for the user to
> have entered their PIN to access the certificate on the card. It may be
> possible to set a timeout on the card, so that the PIN must be reentered
>   to continue transacting.
>
> Thoughts? Comments?
>
> Rogan
> --
> Rogan Dawes
>
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