The IdentityHub in the InternetWide Architecture presents a flexible framework with as many identities as one desires. Let's investigate how useful it can be, and how NFC can help managing it.

Let's say that we visited an event named SHA2017, and that we want to allow the people we meet there to contact us, but as far as possible only them.

In our IdentityHub, we would setup an alias, which is a light-weight extra identity. If our locked-down mailbox name is rick, we might add the name of the event to get rick+sha2017. Any traffic sent to this new address is delivered as we desire, for instance to a new sub-mailbox under our normal one. Special about this alias is that it has its own filtering rules; initially, it will be open to all, but we can set it to close down on, say, November 1st, 2017.

We now turn to spreading the address. We can use it on papers and accounts that we create on behalf of the event, of course. Once the event has been there will be some time for respondents to write to us, after which their chances have ended and we change the mailbox to another policy. Anyone who wrote to us before the policy change will have ended up on a white list and can therefore continue to talk to us as before.

During the event itself, we can spread our contact information using NFC. To that end, we take our business card, which probably has a heavily filtered email address printed on it, and we write a suitable vCard on it in the form of a series of NDEF records. We may add more as well — for example, to facilitate key exchange.

The IdentityHub will support us in downloading the NDEF form holding any of those parts that we desire; it will produce a PGP key for the new identity if we so desire, as well as the vCard showing what we generally consider information worth sharing, all updated to represent the alias instead of our usual contact information. We may download it into our NFC-enabled smartphone, and use that to write the results to our business card. (We tend to forget these things, so it is good being able to do it on the road.)

Anyone we meet can swipe our card to get our event-specific identity, and get in contact with us without any requirement but to be somewhat quick in doing so.

After the event, we should stop using the NDEF records for the event-specific identity. This is easily arranged by overwriting our business card with yet another event's identity. Or, if none presents itself until Februari, we may choose to setup a temporary name or perhaps use our heavily filtered address. Temporary names might be rewritten during SMTP or other interactions, by forwarding contact requests to the actual address. In short, we are in control of our identity, without any real inconvenience for our contact network.

Hope to swipe you at SHA2017!