From c7d7682951d26e5be1907f4e3c18e836915a4263 Mon Sep 17 00:00:00 2001
From: davidsarah <>
Date: Sun, 11 Oct 2009 01:01:22 +0000
Subject: [PATCH] add denial-of-service

[Imported from Trac: page NewCaps/WhatCouldGoWrong, version 6]
---
 NewCaps/WhatCouldGoWrong.md | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/NewCaps/WhatCouldGoWrong.md b/NewCaps/WhatCouldGoWrong.md
index 050b11e..16921bd 100644
--- a/NewCaps/WhatCouldGoWrong.md
+++ b/NewCaps/WhatCouldGoWrong.md
@@ -8,9 +8,12 @@ This is about What Could Go Wrong with the "Elk Point 2" immutable file caps: <h
 |3|forgery of immutable file|generate a matching read-cap (*R*,*T*) for someone else's file|anyone|any one file|the hash function's and cap format's second-pre-image resistance on (*R*,*T*)|2^*n*+*t*^|
 |4|roadblock or speedbump [2]footnote|generate (*K1enc*,*Dhash*,*V*) that hash to someone else's *T*, and copy their *S*|anyone|any one file|the hash function's and cap format's collision resistance on *T*|2^*t*^|
 |5|unauthorized read|attack the encryption of the plaintext with *K1*|anyone|any one file|the cipher's security and the secrecy of the encryption key *K1*|2^*k*^|
-|6|unauthorized read|figure out the input to the hash function that generates *S*|anyone|any one file|the hash function's pre-image resistance on *S*|brute force attack on *R* is !#2|
+|6|unauthorized read|figure out the input to the hash function that generates *S*|anyone|any one file|the hash function's pre-image resistance on *S*|brute force on *R* is !#2|
+|7|unauthorized deletion|brute force KD|anyone|any one file|secrecy of *KD*|
+|8|unauthorized deletion|figure out the destroy key KD from Dhash|anyone|any one file|the hash function's pre-image resistance on *Dhash*|
+|9|denial of service|prevent access to servers holding sufficient shares (by controlling some of them, or by attacking them)|anyone|any file|not prevented by crypto|
 
-where *k* = bitlength(*K1*), *n* = bitlength(*R*), *t* = bitlength(*T*).
+where *k* = bitlength(*K1*), *n* = bitlength(*R*), *t* = bitlength(*T*), *d* = bitlength(*KD*).
 
 1. *shape-shifter immutable file*: creator creates more than one file matching the immutable file readcap
 2. *roadblock*: attacker prevents uploader (including repairer) from being able to write a real share into the right storage index; *speedbump*: attacker adds his bogus share into the list of shares stored under the storage index by the same method; downloader has to download, examine, and discard the bogus (*K1enc*,*Dhash*,*V*)'s until it finds the real one