On Sun, Jan 18, 1998 at 12:45:02PM -0500, Ryan Lackey wrote: [...]
Data disappears from Eternity once no one cares enough about it to pay to have it stored. That could mean someone doesn't pay in advance for the data, or no one is willing to invest disk space in the hope that it will in the future be downloaded.
Providing eternity service costs money. Anything which lets users circumvent this opens up the potential for denial of service through consumption of resources attacks. Even if billing is fundamental, you still have the potential for the NSA to spend $100m to buy all the eternity space available at any point. This is why you also need market mechanisms -- if the NSA is willing to pay a premium for eternity service just to keep it out of the hands of the populace, then running eternity servers is a great investment, so capacity will increase until the NSA can no longer afford to buy all of it.
A difficult part of designing a working Eternity service is to keep people from "stealing service", in terms of consumption of resources, during set up, indexing, etc. Basically, you need to make sure that to the greatest extent possible, anything which is a potentially scarce resource is sold, not given away.
There are alternative ways of paying for the service that do not in any way depend on ecash, and after thinking about it a bit, they seem more robust, as well. The basic idea is as follows: The fundamental eternity service is free to readers, and is financed entirely by writers. The writers supply the disk space, the network bandwidth, and possibly pay for the software to support all this. In a little more detail: you have say 1 megabyte of data that you would like to be stored in the Eternity Service. The overhead of storage in eternity is a factor of two, and you would like 10 times redundancy. So you contact the Eternity Service Software provider, and get the software. You then configure the software to supply 20 megabytes of your disk space to the system. This allows you to supply 1 meg of your own data. The 20 megs will of course not store *your* data -- it will store other eternity data. The service takes your data and spreads it across 10 other sites, whose locations are unknown and unknowable to you. In return, you are storing eternity data for other users. If your disk space becomes unavailable your file disappears from the service. (Of course, someone else could pick it up and store it, if it was valuable information.) This is a self-financing model. Every writer to the eternity service pays for their own bandwidth and disk space. The eternity service provider is financed by maintaining the software that all the writers use -- client/server software will have to run on many different platforms, some protocols may be better than others, and it might be worth buying your eternity software from a high-reputation ("trustworthy") provider. Note that this doesn't mean that data suppliers can't be paid for providing data -- but that is a completely separable problem that can have many different solutions. I believe this approach does solve the financing part. But it does make the rest a *very* complicated problem -- you have a dynamic, self-configuring network of data sources and sinks, with all the configuration data encrypted along with the data. Ideally, of course, the data would be migrating constantly. Retrieval would probably be very slow -- basically email speeds, or worse. In fact, perhaps the data would be retrieved by having the eternity service use the remailer network to send it... -- Kent Crispin "No reason to get excited", kent@songbird.com the thief he kindly spoke... PGP fingerprint: B1 8B 72 ED 55 21 5E 44 61 F4 58 0F 72 10 65 55 http://songbird.com/kent/pgp_key.html