2 files changed, 14 insertions, 0 deletions
diff --git a/src/lib/block/threefish/threefish.cpp b/src/lib/block/threefish/threefish.cpp
index 28a144fb6..99ce135d5 100644
--- a/src/lib/block/threefish/threefish.cpp
+++ b/src/lib/block/threefish/threefish.cpp
@@ -98,6 +98,18 @@ void Threefish_512::skein_feedfwd(const secure_vector<uint64_t>& M,
             m_K[4] ^ m_K[5] ^ m_K[6] ^ m_K[7] ^ 0x1BD11BDAA9FC1A22;
    }
 
+size_t Threefish_512::parallelism() const
+   {
+#if defined(BOTAN_HAS_THREEFISH_512_AVX2)
+   if(CPUID::has_avx2())
+      {
+      return 2;
+      }
+#endif
+
+   return 1;
+   }
+
 std::string Threefish_512::provider() const
    {
 #if defined(BOTAN_HAS_THREEFISH_512_AVX2)
diff --git a/src/lib/block/threefish/threefish.h b/src/lib/block/threefish/threefish.h
index 8fe690f52..cdd27cb11 100644
--- a/src/lib/block/threefish/threefish.h
+++ b/src/lib/block/threefish/threefish.h
@@ -27,6 +27,8 @@ class BOTAN_DLL Threefish_512 final : public Block_Cipher_Fixed_Params<64, 64>
       std::string provider() const override;
       std::string name() const override { return "Threefish-512"; }
       BlockCipher* clone() const override { return new Threefish_512; }
+      size_t parallelism() const override;
+
    protected:
       const secure_vector<uint64_t>& get_T() const { return m_T; }
       const secure_vector<uint64_t>& get_K() const { return m_K; }