Introduce concept Cipher.

Chaos/Cipher/Block/Des/DesCrypt.hpp

@@ -13,6 +13,7 @@
 #include "Cipher/Block/Key.hpp"
 #include "Cipher/Block/Encryptor.hpp"
 #include "Cipher/Block/Decryptor.hpp"
+#include "Cipher/Block/Cipher.hpp"
 
 namespace Chaos::Cipher::Block::Des::Inner_
 {
@@ -524,6 +525,8 @@ private:
     }
 };
 
+static_assert(Cipher::Block::Cipher<DesCrypt>);
+
 } // namespace Chaos::Cipher::Block::Des
 
 #endif // CHAOS_CIPHER_BLOCK_DES_DESCRYPT_HPP