Why biometric authentication isn’t a silver bullet

There has been a lot of noise in the press recently about the rising tide of biometric authentication. The concept has been around for longer than many might think. For example, facial recognition was tested at the Superbowl in 2001, though the results were not widely circulated.

A few pioneering companies (particularly banks) are rolling out biometric trials, such as Standard Chartered in Asia, with finerprint and later voice recognition. In Singapore in particular, two rivals have both piloted voice authentication, DBS for customers dialling their call centre and OCBC for transaction authentication.

It’s not surprising – think of all the positives; easy-to-use, unique to the user, hard to share, tied to the individual’s own physical attributes and frankly, „cool“, as there is a sense of this is how our identities should be verified in a digital age.

Nothing could be meet the „something you are“ requirement than your voice, fingerprint or retina, so how can there be any downsides?

No security solution is without its drawbacks, and in the face of the biometric bandwagon, awareness of the following challenges helps balanced decision-making with all of the facts to hand:

You can’t change a fingerprint or retina scan: whilst of course this is in one sense a strength, it’s also a weakness. If your fingerprint is stolen and then used elsewhere there could be major financial and other wider implications. Unlike refreshing a password, how do you create a new fingerprint? It’s not so easy.

Biometrics are hackable: yes, even your fingerprints are. Tsutomo Masumoto made a working model based on „gummy bear“ material, initially from a live fingerprint and later from a fingerprint left on a physical object.

Creepy vs cool: a recent retail study found signifcant dfferences aomgst consumers in how they viewed a store’s knowledge about them. Whilst some groups saw recognising them by name as they walked the floor as „cool“, others found the possession of certain information to be „creepy“. Not every user wants to share their physical details with a retail outlet for example.

Legalities: data security and privacy are seen as highly important in Germany, and whilst there are variations amongst countries in the way these topics are viewed, who holds biometric data, where they store it, how it is used, and which organisations they share this with have many political, ethical and legal implications, and given how new biometrics are, many legal precedents have not yet been established. Facial recognition is legal in many US states for example, yet in other parts of the world this may not be the case.

False positives: Imagine the accuracy of biometric readings is 98-99% – that’s pretty good, no? Not if you have 10,000 employees entering offices around the world or logging in each day. 98% accuracy means 200 colleagues will not be able to start work on time. Imagine an issue with a fingerprint sensor at an entry door to the building and the queue of impatient co-workers behind the unfortunate blocked user. How many security teams look forward to a mass resetting of entry systems?

Individual use vs high volume: whilst fingerprint recognition might work to access a personal smartphone, it may not be suitable for far higher volume authetication requirements. If hundreds of people are entering a building at the same time,

Don’t underestimate a hacker’s determination: with every new security technology announced, there is sure to be a group of hackers eagerly awaiting the challenge of overcoming it, biometric or not. Retina and facial recognition for example is already being tricked by hi-res photographs of the individual, 3D models and more. Phone calls can be recorded to capture voices, keyboard strokes recorded to learn the typing cadence, and so forth. Whilst this is a lot of work to crack each account, high net worth individuals or celebrities may be viewed as targets worth investing time in.

If you’d like to dive deeper into the topic, there is a great Wired article summarising the legal, technical and ethical complexity involved in biometric authentication.

In the meantime, review any authentication option with an open mind and keep asking the „What if?“ questions. Explore the volume of users, use cases and level of security required; not every solution matches every scenario.