--- a/options.h	Thu Jan 14 21:54:58 2016 +0800
+++ b/options.h	Fri Jan 15 00:19:11 2016 +0800
@@ -152,6 +152,11 @@
  * on x86-64 */
 #define DROPBEAR_ECDSA
 
+/* These larger DH groups (3072 and 4096 bit respectively) add to binary size 
+    and may be significantly slower. Usually ECDH or curve25519 will be a better option */
+/*#define DROPBEAR_DH_GROUP15*/
+/*#define DROPBEAR_DH_GROUP16*/
+
 /* Generate hostkeys as-needed when the first connection using that key type occurs.
    This avoids the need to otherwise run "dropbearkey" and avoids some problems
    with badly seeded /dev/urandom when systems first boot.