diff --git a/src/detail/crypto-helpers.cpp b/src/detail/crypto-helpers.cpp
index 46bca46..b3b9520 100644
--- a/src/detail/crypto-helpers.cpp
+++ b/src/detail/crypto-helpers.cpp
@@ -113,12 +113,6 @@
 const std::vector<uint8_t>&
 ECDHState::deriveSecret(const std::vector<uint8_t>& peerKey)
 {
-  return deriveSecret(peerKey.data(), peerKey.size());
-}
-
-const std::vector<uint8_t>&
-ECDHState::deriveSecret(const uint8_t* peerKey, size_t peerKeySize)
-{
   // prepare self private key
   auto privECKey = EVP_PKEY_get1_EC_KEY(m_privkey);
   if (privECKey == nullptr) {
@@ -131,7 +125,7 @@
   if (peerPoint == nullptr) {
     NDN_THROW(std::runtime_error("TBD"));
   }
-  if (EC_POINT_oct2point(group, peerPoint, peerKey, peerKeySize, nullptr) == 0) {
+  if (EC_POINT_oct2point(group, peerPoint, peerKey.data(), peerKey.size(), nullptr) == 0) {
     EC_POINT_free(peerPoint);
     NDN_THROW(std::runtime_error("Cannot convert peer's key into a EC point when calling EC_POINT_oct2point()"));
   }