[Gzz-commits] manuscripts/bookburnings techreport.rst

[Benja Fallenstein]

CVSROOT:        /cvsroot/gzz
Module name:    manuscripts
Branch:         
Changes by:     Benja Fallenstein <address@hidden>      03/07/16 15:06:42

Modified files:
        bookburnings   : techreport.rst 

Log message:
        bit more

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/manuscripts/bookburnings/techreport.rst.diff?tr1=1.2&tr2=1.3&r1=text&r2=text

Patches:
Index: manuscripts/bookburnings/techreport.rst
diff -u manuscripts/bookburnings/techreport.rst:1.2 
manuscripts/bookburnings/techreport.rst:1.3
--- manuscripts/bookburnings/techreport.rst:1.2 Wed Jul 16 11:51:58 2003
+++ manuscripts/bookburnings/techreport.rst     Wed Jul 16 15:06:42 2003
@@ -7,7 +7,7 @@
 
 :Author:       Benja Fallenstein <address@hidden>
 :Created:      2003-07-13
-:Modified:     $Date: 2003/07/16 15:51:58 $
+:Modified:     $Date: 2003/07/16 19:06:42 $
 
 (the beginning of a summary of the stuff I developed
 while thinking about Storm pointers; need to publish
@@ -55,23 +55,60 @@
 
 .. Digital signatures for updateable documents
 
-A simple approach would be to use 
-
-- Keys expire and are revoked
-- The usual approach: Certificate Authorities (CAs)
-  plus Time Stamping Services (TSSs)
-- For a complete system, also need a
-  Key Archival Service (KAS), which stores the
-  certificate associated with an identity at
-  one time, in order to verify that key K was really
-  the certified public key of entity E at time T
-- Together: KASTS design; non-centralized: Prokopius
-- Good TSS mechanisms patented; the need for
-  something new
-- We present an alternative design which
-  relies on non-patented technology
-- We show that attacks on our system have
-  equivalents in a KASTS system
+A simple approach would be to use digital signatures.
+A document could be identified by a cryptographic
+public key; all versions signed by the corresponding
+private key would be considered versions of the
+document.
+
+.. Keys expire and are revoked
+
+However, public key cryptography relies on the
+keeping of secrets-- the private keys. Since there
+is no perfect way of guarding a secret, a key
+may be stolen; then, there must be a way for
+the publisher to 'revoke' the key-- i.e., to
+say that signatures given with this key cannot
+be trusted any longer.
+
+However, if all signatures given with a key
+become invalid, then old versions of a document
+could not be retrieved any longer.
+
+.. The usual approach: Certificate Authorities (CAs)
+   plus Time Stamping Services (TSSs)
+
+The usual solution to this problem is to use
+digital timestamping, which certifies that
+a certain digital document existed at a given time.
+If, using timestamping, we can verify that a signature
+was provided before the corresponding key was revoked, 
+the signature continues to be valid even after
+revocation.
+
+Unfortunately, while there are good methods to
+timestamp documents in a secure, trusted way,
+these methods are patented. 
+
+In this document, we describe a system 
+providing the equivalent of digital signatures
+(verifiable statements of the form: "Authority A
+approved of message B") without relying on 
+patented timestamping technology.
+
+..
+    - For a complete system, also need a
+      Key Archival Service (KAS), which stores the
+      certificate associated with an identity at
+      one time, in order to verify that key K was really
+      the certified public key of entity E at time T
+    - Together: KASTS design; non-centralized: Prokopius
+    - Good TSS mechanisms patented; the need for
+      something new
+    - We present an alternative design which
+      relies on non-patented technology
+    - We show that attacks on our system have
+      equivalents in a KASTS system
 
 
 An "A said that B said that C said..." approach