diff --git a/src/crypto/elliptic.cpp b/src/crypto/elliptic.cpp
index d4cf5cb..cedad1d 100644
--- a/src/crypto/elliptic.cpp
+++ b/src/crypto/elliptic.cpp
@@ -279,8 +279,9 @@ struct ssl_bignum
         BN_mod(secexp, secexp, order, ctx);
 
         fc::sha256 secret;
-        assert(BN_num_bytes(secexp) == sizeof(secret));
-        BN_bn2bin(secexp, (unsigned char*)&secret);
+        assert(BN_num_bytes(secexp) <= int64_t(sizeof(secret)));
+        auto shift = sizeof(secret) - BN_num_bytes(secexp);
+        BN_bn2bin(secexp, ((unsigned char*)&secret)+shift);
         return regenerate( secret );
     }