On Mon, 20 May 1996 jamesd@echeque.com wrote:

...

Look up cypernomicon, "open encrypted books"

At 01:30 PM 5/20/96 -0700, Wei Dai wrote:

There is indeed a short section in the Cyphernomicon about encrypted open books. Unfortunately it doesn't describe it in detail,

An organization, such as a bank, issues signed, non anonymous promises to pay to various nyms -- in other words bank accounts, or interest bearing bonds, or some such. A nym would like to know what the total amount of such signed obligation is, so that he can be sure it is less than the total value of the institutions good name and readily findable and confiscatable assets. But we do not want a bunch of outsiders getting a list of lots of private information about who owns what, (such as auditors who are usually in the pockets of the tax collectors). The institution needs to be able to prove that it only owes total amount X in this form, without letting Tom, Dick, and Harry know who it owes amount X to, and why. To do this it organizes its accounts in a binary tree, and constructs a one way checksum tree checksum, revealing to each custom the part of the tree he is on, all the way up to the root, which must be the same for all customers, and must be placed in some public place, so that any customer can tell that his account is included in the total openly admitted obligations of the institution, and any customer can, by revealing secret information, prove that he is one of the people that the institution has publicly admitted owing money to. --------------------------------------------------------------------- | We have the right to defend ourselves | http://www.jim.com/jamesd/ and our property, because of the kind | of animals that we are. True law | James A. Donald derives from this right, not from the | arbitrary power of the state. | jamesd@echeque.com