sign def added

ACNS/presentation/preamble.tex

@@ -117,6 +117,7 @@
 \newcommand\decaps{\mathsf{Decaps}}
 \newcommand\encaps{\mathsf{Encaps}}
 \newcommand\keygen{\mathsf{KeyGen}}
+\newcommand\sign{\mathsf{Sign}}
 \providecommand\highlight[1]{\emph{#1}}
 
 \DeclarePairedDelimiter{\paren}{\lparen}{\rparen}