The Gevulot

‘It’s a nice thought.’ He offers her his hand. ‘I am Paul. I got a little lost: all those moving streets. I was hoping you could tell me the way out.’

A trickle of emotion bleeds through his rough visitor’s gevulot: a sense of unease, a weight, a guilt. Xuexue can imagine the old man of the sea sitting on his back. It feels very familiar. And suddenly it is more important to talk to the stranger than to smile at the robot.

‘Sure I can,’ she says. ‘But why don’t you stay for a little while? What brings you to the Oubliette?’ As she speaks, she crafts a gevulot contract in her mind and offers it to Paul. He blinks. ‘What is that?’

‘No one else will remember or know what we are going to say here,’ she says. ‘Even I will forget, unless you let me remember.’ She smiles. ‘This is the way things work here. No one has to be a stranger.’

‘It’s like you have a portable confession booth.’

‘Something like that.’

[...]

‘This is how it works. The exomemory stores data – all data – that the Oubliette gathers, the environment, senses, thoughts, everything. The gevulot keeps track of who can access what, in real time. It’s not just one public/private key pair, it’s a crazy nested hierarchy, a tree of nodes where each branch can only by unlocked by the root node. You meet someone and agree what you can share, what they can know about you, what you can remember afterwards.’

‘Sounds complicated.’

‘It is. The Martians have a dedicated organ for it.’ I tap my head. ‘A privacy sense. They feel what they are sharing, what is private and what isn’t. They also do something called co-remembering, sharing memories with others just by sharing the appropriate key with them. We just have the baby version. They give the visitors a bit of exomemory and an interface to it, reasonably well-defined. But there is no way we can appreciate the subtleties.’

[...]

The way gevulot works is by generating a tree of public and private key pairs: a new pair is generated whenever the user has a new memory, domain or experience they want to specify gevulot rights for. They are also encrypted with the pair above them in the hierarchy. The point is that only the individual is supposed to have access to the root.

Except that it looks like all the roots are also generated from another pair. A master key, if you like. Whoever holds those is able to access every exomemory in the Oubliette, and to rewrite them. For people who pass through Quiet, that means their entire mind. That’s where these new edits to Unruh’s mind came from. The cryptarchs must have some sort of automated system that modifies everybody who passes through the Quiet.

A device that provides privacy protection with anyone you interact with real or virtual.