> With IRMA it is easy to log in and make yourself known, by disclosing only relevant attributes of yourself. For instance, in order to watch a certain movie online, you prove that you are older than 16, and nothing else.

That’s not “cool stuff”.

Besides, at least around here they already ask for an ID if you look young enough, for some movies. This is not enabled by new technologies.

For the unfamiliar, with identity-based encryption, the recipient's public key is a function of the key authority's public key and some "identity", such as a national ID number or email address. Their private key is a one-way function of their identity and the key authority's private key. So, the recipient needs to ask the key authority one time to generate their private key for them, but there's only one public key to distribute. For the whole system, the sender can calculate the recipient's public key. The private key isn't even necessarily calculated before the sender has sent their message! It's very convenient and flexible!

Of course, the downside is that the private key is deterministic and can always be re-generated by the key authority, so it's fundamentally vulnerable to attack by the key authority. Also, some of the underlying math is less well studied than standard ECDHE/DHE/RSA, so we're less confident about vulnerabilities lurking just under the surface.

Right now most platforms don't do ID validation because users hate sharing their details. By making it more privacy-safe more platforms will do it because the barrier is lower. I really hate that, I think the internet should remain anonymous. So I can pick whatever nick and even have multiple.