Authentication

Airport Security in the Age of COVID-19

As the travel restrictions imposed to control the coronavirus pandemic are beginning to be relaxed in some parts of the world, it is time to start rethinking airport security in the age of COVID-19. Even if an effective vaccine is found for COVID-19, it will be out of the question to go back to long lines at security checkpoints and boarding gates, and the manual checking of identity documents and boarding passes.

In a provisional patent application that I coauthored with Karen Lewison before the pandemic and have now published, we proposed an automated method of verifying the identity of travelers that could be used in the post-pandemic world to speed up the security check and the boarding process, and to eliminate the face-to-face interaction with a security officer at the checkpoint and a flight attendant at the boarding gate. The method takes advantage of the high accuracy achieved by today’s deep neural networks for face recognition, while overcoming the privacy concerns raised by the collection and storage of facial images.

Here is a summary of the method.

Identity Verification: A Coronavirus Challenge to the Financial World

Updated April 1st, 2020

This blog post has been coauthored with Karen Lewison

The coronavirus pandemic is causing unprecedented disruption throughout the business world. Businesses that are not able to cope with public health orders and new customer behaviors are going out of business, while businesses that are able to adapt are thriving and expanding their market share. Disruption will be temporary in sectors of the economy where face-to-face interaction adds value to the business-to-customer relationship and a physical presence on the street is an essential requirement of the business model; gyms, bars and conference centers will no doubt reopen once the pandemic has been controlled. But changes brought by the pandemic will be permanent in sectors of the economy where face-to-face interaction adds no value and a physical presence is a legacy of a traditional business model. One of those sectors is the financial world.

A challenge to financial institutions

Financial institutions have been less impacted than other businesses by the pandemic. In the US, the entire financial sector has been declared critical infrastructure by DHS and is thus protected against closure orders by states or counties. And most financial transactions are now conducted online using web browsers or mobile apps, without face-to-face interactions that would put employees and customers at risk of contagion. Nevertheless, coronavirus poses a challenge to financial institutions: how to verify the identity of new customers.

Pomcor Granted Patent on Rich Credentials

Pomcor has been granted US Patent 10,567,377, Multifactor Privacy-Enhanced Remote Identification Using a Rich Credential. Karen Lewison is the lead inventor and I am a coinventor. Pomcor has so far been granted a total of eight patents, two of which we have sold. The remaining six patents that we own are listed in the Patents page of this web site.

This latest patent is special because it provides a solution to a major societal problem: how to identify people over the Internet with strong security. Techniques are available for authenticating repeat visitors to a web site or current users of a web application. But authentication techniques are only applicable once a relationship has been established. They are not applicable when somebody wants to establish a new relationship, e.g. by becoming a new customer of a bank, or signing up with a robo advisor, or applying for a mortgage, or renting an apartment, or switching to a different car insurance.

A New Tool Against the Surge of Application Fraud

This blog post has been coauthored with Karen Lewison

In recent posts we have been concerned with online credit card fraud and how to fight it using cardholder authentication. In this post we are concerned with another kind of financial fraud, known as application fraud or new account fraud. Both kinds of fraud have been rising after the introduction of chip cards, for reasons mentioned by Elizabeth Lasher in her article The Surge of Application Fraud:

“Due to the high volume of data breaches, Social Security numbers, mailing addresses, passwords, health history, even the name of our first pet is all for sale on the Dark Web. When you combine this phenomenon with the economic pressure applied on fraudsters to find a new cash cow after chip and signature plugged a gap in card-present fraud in the US, there is a perfect storm.”

The term “application fraud” refers to the creation of a financial account, such as a bank account or a mortgage account, with the intention to commit fraud. Application fraud can be first-party fraud, where the account is opened under the fraudster’s own identity, or third-party fraud, where the fraudster uses a stolen identity. Here we are primarily concerned with the latter.

PSD2 Is In Trouble: Will It Survive?

This blog post has been coauthored with Karen Lewison

The 2nd Payment Services Directive (PSD2) of the European Union went into effect on September 14, but one of its most prominent provisions, the Strong Customer Authentication (SCA) requirement, was postponed until December 31, 2020 by an opinion dated 16 October 2019 of the European Banking Authority (EBA). The EBA cited pushback from the National Competent Authorities (NCAs) of the EU member countries as the reason for the postponement, and the fact that version 2 of the 3-D Secure protocol (3-D Secure 2) is not ready as a reason for the pushback.

PSD2 is supposed to be technology neutral, but the EBA has unequivocally endorsed 3-D Secure as the way to implement the SCA requirement for online credit card transactions, as stated in another opinion, dated 21 June 2019:

Will Cardholder Authentication Ever Come to the US?

This blog post has been coauthored with Karen Lewison

You may have heard that the EU is struggling to implement the Strong Customer Authentication (SCA) requirements of Payment Services Directive 2 (PSD2). The directive was issued four years ago, Regulatory Technical Standards (RTS) followed two years later, and the SCA requirements went into effect on September 14. But on October 16 the European Banking Authority (EBA) had to postpone enforcement until December 31, 2020, due to pushback from the National Competent Authorities (NCAs) of the EU member countries. In an opinion announcing the postponement, the EBA cited as a reason for the pushback the fact that 3-D Secure 2 (3DS2) is not ready.

The problems that the EBA is having with the SCA requirements have more to do with the bureaucratic formulation of the requirements in PSD2, than with the technical difficulty of providing strong security. We will discuss this in another post, but first we want to ask here whether cardholder authentication will ever come to the US.

3-D Secure 2 May Allow the Merchant to Impersonate the Cardholder

3-D Secure is a protocol that provides security for online credit card payments by redirecting the cardholder’s browser to the web site of the bank that has issued the credit card, where the cardholder is authenticated by methods such as username-and-password or a one-time password. 3-D Secure is rarely used in the US because the cardholder authentication creates friction that may cause transaction abandonment, but it is used more frequently in other countries. The credit card networks have been working on a new version of the protocol, called 3-S Secure 2, where the issuing bank assesses fraud risk based on information received from the merchant through a back channel and waives authentication for low-risk transactions.

In a paper presented at HCII 2019 we showed that 3-D Secure 2 has serious privacy and usability issues and we proposed an alternative protocol that provides strong security without friction for all transactions by cryptographically authenticating the cardholder. We have now looked in more detail at a particular configuration of 3-D Secure 2 where the cardholder uses a native app instead of a browser to access the merchant’s site, and we have found security flaws, described in detail in a technical report, that may allow a malicious merchant to impersonate the cardholder.

Online Cardholder Authentication without Accessing the Card Issuer’s Site

One of the saddest failings of Internet technology is the lack of security for online credit card transactions. In in-store transactions, the cardholder authenticates by presenting the card, and card counterfeiting has been made much more difficult by the addition of a chip to the card. But in online transactions, the cardholder is still authenticated by his or her knowledge of credit card and cardholder data, a weak secret known by many.

Credit card networks have been trying to provide security for online transactions for a long time. In the nineties they proposed a complicated cryptographic protocol called SET (Secure Electronic Transactions) that was never deployed. Then they came up with a simpler protocol called 3-D Secure, where the merchant redirects the cardholder’ browser to the issuing bank, which asks the cardholder to authenticate with a password. 3-D Secure is rarely used in the US and unevenly used in other countries, due to the friction that it causes and the risk of transaction abandonment; lately some issuers have been asking for a second authentication factor, adding more friction. Now the networks have come up with version 2 of 3-D Secure, which removes friction for low risk transactions by introducing a “frictionless flow”. But the frictionless flow does not authenticate the cardholder. Instead, the merchant sends device and cardholder data to the issuer through a back channel, potentially violating the cardholder’s privacy.

Last August we wrote a blog post and a paper proposing a scheme for authenticating the cardholder without friction using a cryptographic payment credential consisting of a public key certificate and the associated private key. We have recently written a revised version of the paper with major improvements to the scheme. The paper will be presented next month at HCII 2019 in Orlando.

Pomcor Contributes Biometrics Chapter to HCI and Cybersecurity Handbook

Karen Lewison and I have contributed the chapter on Biometrics to the book Human-Computer Interaction and Cybersecurity Handbook, published by Taylor & Francis in the CRC Press series on Human Factors and Ergonomics. The editor of the paper, Abbas Moallem, has received the SJSU 2018 Author and Artist Award for the book.

Biometrics is a very complex topic because there are many biometric modalities, and different modalities use different technologies that require different scientific backgrounds for in-depth understanding. The chapter focuses on biometric verfication and packs a lot of knowledge in only 20 pages, which it organizes by identifying general concepts, matching paradigms and security architectures before diving into the details of fingerprint, iris, face and speaker verification, briefly surveying other modalities, and discussing several methods of combining modalities in biometric fusion. It emphasizes presentation attacks and mitigation methods that can be used in what will always be an arms race between impersonators and verifiers, and discusses the security and privacy implications of biometric technologies.

Feedback or questions about the chapter would be very welcome as comments on this post.

Frictionless Secure Web Payments without Giving up on Cardholder Authentication

The 3-D Secure protocol version 1.0, marketed under different names by different payment networks (Verified by Visa, MasterCard SecureCode, American Express SafeKey, etc.) aims at reducing online credit card fraud by authenticating the cardholder. To that purpose, the merchant’s web site redirects the cardholder’s browser to the issuing bank, which typically authenticates the cardholder by asking for a static password and/or a one-time password delivered to a registered phone number. 3-D Secure was introduced by Visa in 1999, but it is still unevenly used in European countries and rarely used in the United States. One reason for the limited deployment of 3-D Secure is the friction caused by requiring users to remember and enter a password and/or retrieve and enter a one-time password. Consumers “hate” 3-D Secure 1.0, and merchants are wary of transaction abandonment. Another reason may be that it facilitates phishing attacks by asking for a password after redirection, as discussed here, here, and here.

3-D Secure 2.0 aims at reducing that friction. When 3-D Secure 2.0 is deployed, it will introduce a frictionless flow that will eliminate cardholder authentication friction for 95% of transactions deemed to be low risk. But it will do so by eliminating cardholder authentication altogether for those transactions. The merchant will send contextual information about the intended transaction to the issuer, including the cardholder’s payment history with the merchant. The issuer will use that information, plus its own information about the cardholder and the merchant, to assess the transaction’s risk, and will communicate the assessment to the merchant, who will redirect the browser to the issuer for high risk transactions but omit authentication for low risk ones.

This new version of 3-D Secure has serious drawbacks. It is privacy invasive for the cardholder. It puts the merchant in a bind, who has to keep customer information for the sake of 3D-Secure while minimizing and protecting such information to comply with privacy regulations. It is complex for the issuer, who has to set up an AI “self-learning” risk assessment system. It requires expensive infrastructure: the contextual information that the merchant sends to the issuer goes through no less than three intermediate servers—a 3DS Server, a Directory Server and an Access Control server. And it provides little or no security benefit for low risk transactions, as the cardholder is not authenticated and the 3-D Secure risk assessment that the issuer performs before the merchant submits the transaction to the payment network is redundant with the risk assessment that it performs later before authorizing or declining the submitted transaction forwarded by the payment network.

There is a better way. In a Pomcor technical report we propose a scheme for securing online credit card payments with two-factor authentication of the cardholder without adding friction.