+#define THREEFISH256_BLOCKSIZE 256
+#define THREEFISH256_BLOCKSIZE_B ((THREEFISH256_BLOCKSIZE+7)/8)
+#define THREEFISH512_BLOCKSIZE 512
+#define THREEFISH512_BLOCKSIZE_B ((THREEFISH512_BLOCKSIZE+7)/8)
+#define THREEFISH1024_BLOCKSIZE 1024
+#define THREEFISH1024_BLOCKSIZE_B ((THREEFISH1024_BLOCKSIZE+7)/8)
+
+/** \typedef threefish256_ctx_t
+ * \brief holds key data for Threefish-256
+ *
+ * A variable of this type may hold the key data for Threefish-256 encryption
+ * or decryption..
+ */