X-Git-Url: https://git.distorted.org.uk/~mdw/doc/ips/blobdiff_plain/76f457cbe78101034f0254a9ea940ca65cee1535..53aa10b5d9431ced4e98673cc872c6627cac1d5f:/auth-sig.tex diff --git a/auth-sig.tex b/auth-sig.tex index b3322ac..8faff1e 100644 --- a/auth-sig.tex +++ b/auth-sig.tex @@ -29,7 +29,7 @@ We recognize several different types of forgeries which can be made: \begin{itemize} - \item An \emph{existiential forgery} occurs when an adversary creates a + \item An \emph{existential forgery} occurs when an adversary creates a valid signature for some arbitrary message not of its choosing. \item An \emph{selective forgery} occurs when an adversary creates a valid signature for a message that it chooses. @@ -183,9 +183,9 @@ \end{slide} \begin{slide} - \head{Fixing RSA, 2: \PKCS1 padding (cont.)} + \head{\PKCS1 signature padding (cont.)} - Diagramatically, \PKCS1 signature looks like this: + Diagrammatically, \PKCS1 signature looks like this: \begin{tabular}[C]{r|c|c|c|c|c|} \hlx{c{2-6}v} \hex{00} & \hex{01} & \hex{FF} \hex{FF} \ldots \hex{FF} & @@ -314,7 +314,7 @@ \[ \Pr[F] = \Pr[F \land N] + \Pr[F \land \lnot N] \quad \text{so} \quad \Pr[F \land \lnot N] = \Pr[F] - \Pr[F \land N]. \]% - From the above discussion, we ahave + From the above discussion, we have \[ \Pr[V \land N] = \Pr[F \land N] \quad \text{and} \quad \Pr[V \land \lnot N] \ge \frac{1}{q_H} \Pr[F \land \lnot N]. \]% @@ -563,7 +563,7 @@ Most of the \ABORT statements in the main inverter routine detect incorrect signatures. The final one, asserting $x \notin \Xid{I}{map}$, can't happen - unless the signaure is a duplicate of one we already gave. + unless the signature is a duplicate of one we already gave. The \ABORT{}s in $H$ and \id{sign} detect conditions in which the adversary has successfully distinguished its simulated environment from