From 5501983f5f6ca0673f113427c357724652573581 Mon Sep 17 00:00:00 2001 From: Brian Warner Date: Sat, 11 Jul 2009 14:25:00 +0100 Subject: [PATCH] proposed/mutable-DSA.txt: add some new design criteria --- docs/proposed/mutable-DSA.txt | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/docs/proposed/mutable-DSA.txt b/docs/proposed/mutable-DSA.txt index 5cfb30d6..c36dc8a0 100644 --- a/docs/proposed/mutable-DSA.txt +++ b/docs/proposed/mutable-DSA.txt @@ -10,6 +10,39 @@ This file shows only the differences from RSA-based mutable files to (EC)DSA-based mutable files. You have to read and understand mutable.txt before reading this file (mutable-DSA.txt). +== new design criteria == + +* provide for variable number of semiprivate sections? +* put e.g. filenames in one section, readcaps in another, writecaps in a third + (ideally, to modify a filename you'd only have to modify one section, and + we'd make encrypting/hashing more efficient by doing it on larger blocks of + data, preferably one segment at a time instead of one writecap at a time) +* cleanly distinguish between "container" (leases, write-enabler) and + "slot contents" (everything that comes from share encoding) +* sign all slot bits (to allow server-side verification) +* someone reading the whole file should be able to read the share in a single + linear pass with just a single seek to zero +* writing the file should occur in two passes (3 seeks) in mostly linear order + 1: write version/pubkey/topbits/salt + 2: write zeros / seek+prefill where the hashchain/tree goes + 3: write blocks + 4: seek back + 5: write hashchain/tree +* storage format: consider putting container bits in a separate file + - $SI.index (contains list of shnums, leases, other-cabal-members, WE, etc) + - $SI-$shnum.share (actual share data) +* possible layout: + - version + - pubkey + - topbits (k, N, size, segsize, etc) + - salt? (salt tree root?) + - share hash root + - share hash chain + - block hash tree + - (salts?) (salt tree?) + - blocks + - signature (of [version .. share hash root]) + === SDMF slots overview === Each SDMF slot is created with a DSA public/private key pair, using a -- 2.45.2