Clarify comment in program
diff --git a/programs/pkey/ecdsa.c b/programs/pkey/ecdsa.c
index 0b4f8c4..40d67da 100644
--- a/programs/pkey/ecdsa.c
+++ b/programs/pkey/ecdsa.c
@@ -182,6 +182,10 @@
/*
* Transfer public information to verifying context
+ *
+ * We could use the same context for verification and signatures, but we
+ * chose to use a new one in order to make it clear that the verifying
+ * context only needs the public key (Q), and not the private key (d).
*/
printf( " . Preparing verification context..." );
fflush( stdout );