Aadhaar is insecure because it is based on biometrics. Biometrics is surveillance technology, a necessity for any State. However, surveillance is much like salt in cooking: essential in tiny quantities, but counterproductive even if slightly in excess. Biometrics should be used for targeted surveillance, but this technology should not be used in e-governance for the following reasons:

One, biometrics is becoming a remote technology. High-resolution cameras allow malicious actors to steal fingerprints and iris images from unsuspecting people. In a couple of years, governments will be able to identify citizens more accurately in a crowd with iris recognition than the current generation of facial recognition technology.

Two, biometrics is covert technology. Thanks to sophisticated remote sensors, biometrics can be harvested without the knowledge of the citizen. This increases effectiveness from a surveillance perspective, but diminishes it from an e-governance perspective.

Three, biometrics is non-consensual technology. There is a big difference between the State identifying citizens and citizens identifying themselves to the State. With biometrics, the State can identify citizens without seeking their consent. With a smart card, the citizen has to allow the State to identify them. Once you discard your smart card the State cannot easily identify you, but you cannot discard your biometrics.

Four, biometrics is very similar to symmetric cryptography. Modern cryptography is asymmetric. Where there is both a public and a private key, the user always has the private key, which is never in transit and, therefore, intermediaries cannot intercept it. Biometrics, on the other hand, needs to be secured during transit. The UIDAI’s (Unique Identification Authority of India overseeing the rollout of Aadhaar) current fix for its erroneous choice of technology is the use of “registered devices”; but, unfortunately, the encryption is only at the software layer and cannot prevent hardware interception.

Five, biometrics requires a centralised network; in contrast, cryptography for smart cards does not require a centralised store for all private keys. All centralised stores are honey pots — targeted by criminals, foreign States and terrorists.

Six, biometrics is irrevocable. Once compromised, it cannot be secured again. Smart cards are based on asymmetric cryptography, which even the UIDAI uses to secure its servers from attacks. If cryptography is good for the State, then surely it is good for the citizen too.

Seven, biometrics is based on probability. Cryptography in smart cards, on the other hand, allows for exact matching. Every biometric device comes with ratios for false positives and false negatives. These ratios are determined in near-perfect lab conditions. Going by press reports and even UIDAI’s claims, the field reality is unsurprisingly different from the lab. Imagine going to an ATM and not being sure if your debit card will match your bank’s records.

Eight, biometric technology is proprietary and opaque. You cannot independently audit the proprietary technology used by the UIDAI for effectiveness and security. On the other hand, open smart card standards like SCOSTA (Smart Card Operating System for Transport Applications) are based on globally accepted cryptographic standards and allow researchers, scientists and mathematicians to independently confirm the claims of the government.

Nine, biometrics is cheap and easy to defeat. Any Indian citizen, even children, can make gummy fingers at home using Fevicol and wax. You can buy fingerprint lifting kits from a toystore. To clone a smart card, on the other hand, you need a skimmer, a printer and knowledge of cryptography.

Ten, biometrics undermines human dignity. In many media photographs — even on the @UIDAI's Twitter stream — you can see the biometric device operator pressing the applicant's fingers, especially in the case of underprivileged citizens, against the reader. Imagine service providers — say, a shopkeeper or a restaurant waiter — having to touch you every time you want to pay. Smart cards offer a more dignified user experience.

Eleven, biometrics enables the shirking of responsibility, while cryptography requires a chain of trust.

Each legitimate transaction has repudiable signatures of all parties responsible. With biometrics, the buck will be passed to an inscrutable black box every time things go wrong. The citizens or courts will have nobody to hold to account.

The precursor to Aadhaar was called MNIC (Multipurpose National Identification Card). Initiated by the NDA government headed by Atal Bihari Vajpayee, it was based on the open SCOSTA standard. This was the correct technological choice.

Unfortunately, the promoters of Aadhaar chose biometrics in their belief that newer, costlier and complex technology is superior to an older, cheaper and simpler alternative.

This erroneous technological choice is not a glitch or teething problem that can be dealt with legislative fixes such as an improved Aadhaar Act or an omnibus Privacy Act. It can only be fixed by destroying the centralised biometric database, like the UK did, and shifting to smart cards.

In other words, you cannot fix using the law what you have broken using technology.