diff --git a/library/ecp.c b/library/ecp.c
index c8dd7f0080..9d2d72ccae 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -24,9 +24,11 @@
  * GECC = Guide to Elliptic Curve Cryptography - Hankerson, Menezes, Vanstone
  * FIPS 186-3 http://csrc.nist.gov/publications/fips/fips186-3/fips_186-3.pdf
  * RFC 4492 for the related TLS structures and constants
+ * - https://www.rfc-editor.org/rfc/rfc4492
  * RFC 7748 for the Curve448 and Curve25519 curve definitions
+ * - https://www.rfc-editor.org/rfc/rfc7748
  *
- * [Curve25519] http://cr.yp.to/ecdh/curve25519-20060209.pdf
+ * [Curve25519] https://cr.yp.to/ecdh/curve25519-20060209.pdf
  *
  * [2] CORON, Jean-S'ebastien. Resistance against differential power analysis
  *     for elliptic curve cryptosystems. In : Cryptographic Hardware and