Friday, September 20, 2019

Do not Rely Solely...

I often tell small children that "in the future most of your toys will talk and listen and generally tell the truth; when in doubt ask Dad."

However, this is the age of disinformation, "fake news," and state propaganda.  Our children will confront errors and deliberate lies.  At some level, we all know that Fox, CNN, and MSNBC have agendas, biases, that make them less than totally reliable.  We need to equip our children to recognize and cope.  

I like Wikipedia, I think that it is one of humanity's greatest achievements, in part because it relies for its authority on its users.  Teachers question the authority of Wikipedia: they prefer the Britannica, in part because it relies for its authority on scholars like themselves.  They prefer it even though it is only one-sixth the size of Wikipedia and much more difficult to use.  However every night when I go to bed, I give thanks that Wikipedia is a little better than it was when I got up in the morning while the Britannica is just as bad.  Wikipedia is self correcting.  

The net is that we want our children to think critically, to be skeptical, to be able to separate facts from opinion, what is important from that which is trivial, to prefer primary sources, to prefer neutral sources, PBS and C-SPAN before Fox or MSNBC.  Perhaps the single most important tool that we can teach them is to check multiple sources.  

Security by Obscurity

According to Wikipedia, "Security through obscurity is the reliance in security engineering on design or implementation secrecy as the main method of providing security to a system or component. Security experts have rejected this view as far back as 1851, and advise that obscurity should never be the only security mechanism."  Labeling the other guy's security strategy as "security by obscurity" is how we disparage it.  

However, looked at another way, all information security is about secrecy, if not obscurity.  What we think of as security can be seen as the collection of mechanisms that we use to reduce the size and number of the secrets that we must keep. 

Encrypting an object reduces the problem of hiding the file to one of hiding only the key.  Access control may reduce the problem of hiding user capabilities and privileges to one of hiding the user password.  

Wednesday, September 18, 2019

Out of Band Confirmation

This morning I sent a gift via PayPal to a family member, one to whom I had never sent one in the past.  The transaction was initiated using the PayPal iOS app.  It included an out of band one time password and was from a device that PayPal recognized.  Almost immediately, I got an e-mail confirming the transaction.  About an hour later, I received an SMS message from PayPal asking me to confirm that I had initiated the transaction.    When the charge hits my little four branch community bank, I will receive another e-mail and another SMS from them.  Incidentally, I also got a "thank you" e-mail from the family member.

If I had used a new device to initiate my transaction, the web instead of the app, or changed my e-mail, cell number, or bank accounts, PayPal would have confirmed those activities.  For changes to my e-mail or cell number in my PayPal profile, PayPal would confirm those changes to the other address and for the address changed to both the new and the old addresses.   So will, for example, American Express, Fidelity, BoA, and Chase.

How much of this is by design, I do not know.  What I do know is that, if my transaction was not properly authorized, PayPal, my bank, and I would have ample opportunity to learn about it on a timely basis.  

Having two or more addresses for our customers, two ways to get a message to a device carried in one's hand, pocket, or purse, makes this control more effective than ever.  The cheap and fast communication provided by the modern public networks makes them so efficient that it could be considered negligent, even reckless, not to use them.  

What continues to concern me is that when I go to fraud conferences, I may be the only one to talk about "out of band confirmations," perhaps the single most powerful fraud detection mechanism that we have.  

Please put this tool in your kit.  Promote it every chance you get.  Ensure that it is included in all your applications.  Confirm all transactions and new or changed user profile data.  Confirm to every address that you have.  Confirm address changes, postal, e-mail, phone numbers, and device identities, to both the old and the new address.

Monday, September 9, 2019

Apple Titanium Card

I have been waiting for the delivery of my Titanium Card to be delivered to write this evaluation.  Read it in the context of my last post.  

The card is delivered via FedEx in a large envelope.  There is a return address but it does not say "Apple."  This resists theft of the card in transit.

Inside the FedEx envelope is a tamper evident 4.5" x 6.25" x 0.25" corrugated cardboard package containing the card.  This protects against tampering with or skimming the card in transit.  

While a signature is not required for delivery, one gets a notification of delivery.  This may narrow the window of opportunity for theft from the doorstep.  

Only after receipt does one see the button in the Wallet App to "activate" the card.  This resists any use of the card prior to receipt by the legitimate owner.  

While the owner's name is on the face of the card, the card number, expiration date, and the CVV are not.  While the number is on the magnetic strip, unlike with all other cards, it is different from the number that one would use at an e-commerce site.  Thus, the only way that one might monetize knowledge of the number would be to use it to counterfeit a card.  

Note that any fraudulent use of the number on the stripe will show up immediately on the owner's iPhone so that the transaction can be reported as fraudulent and the number can be reported as compromised.  Skimming the number and counterfeiting a card for one or two uses is a high hurdle.  

The value on the magnetic stripe, provided for backwards compatibility, on a card which will be used sparingly, is a limited vulnerability.  From a security perspective, consumers should prefer Apple Pay (using iPhone of Apple Watch), EMV, manual entry of the number (from the iPhone Wallet App), and swiping the magnetic stripe in that order.  While the magnetic stripe is more convenient than manual entry, many users may never have to use either.  As point of sale devices are modernized, the requirement for any alternative to contactless or "chip" will decline.  

Finally, in the app, one can disable and enable the card.  Thus one can carry the card while mitigating the risk of fraudulent use should it be lost or stolen.  Since I expect the use of the Titanium card to be sparse, mine remains disabled by default.  Others may choose to leave it enabled by default, disabling it only should it be lost or stolen.

The vulnerability of the number on the magnetic stripe is not limited to the Titanium card; so far it is not possible to get any other credit card without this vulnerability.  On the other hand, the Titanium card does not have the vulnerability of having the primary account number, the expiration date, and the CVV on the face.  Therefore, if one is going to carry a credit of debit card with a number in the clear on the magnetic stripe, the Titanium card is the clear favorite.  

(Incidentally, I convinced myself.  I got the Titanium card, intending to put it in the drawer and never carry it.)