QUOTE : 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 be 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.