Zero-Knowledge Protocols

As we have already seen with the digital signature, the authentication problem is one of the most important, complicated, and intriguing challenges that cryptography is going to face in the near future. Imagine that you want to identify yourself to someone who doesn’t know you online. First, you will be asked to provide your name, surname, and address; going deeper, you will be asked for your social security number and other sensitive data that identifies you. Of course, you know that exposing such data via the internet can be very dangerous because someone might steal your private information and use it for nefarious purposes.

Hackers know everything about their victims’ lives – finances, assets owned, and even credit card numbers. If a hacker knows your identity, they can easily find out about most of your digital life.

In another case, you might have read a news story where a gang of thieves planted a fake ATM in a commercial...