Add Greg Chapman.
diff --git a/Misc/ACKS b/Misc/ACKS
index 0e9e07f..6858a93 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -74,6 +74,7 @@
 Per Cederqvist
 Jeffrey Chang
 Brad Chapman
+Greg Chapman
 Mitch Chapman
 David Chaum
 Nicolas Chauvat