std::string da_key(reinterpret_cast<const char*>(&G.k[0]),
						G.k.SizeInBytes() * 8); // we need the size in bits
		std::string a{fortuna::Util::do_sha(da_key + s)};
		std::memmove(&G.k[0], &a[0], G.k.SizeInBytes());
		r += do_crypto();
static auto do_sha(const std::string& str_to_hash) -> const std::string {
	// do sha256
	std::string digest;

	// no reason not to go for Keccak
	CryptoPP::SHA3_256 sha3_256;

	CryptoPP::StringSource str_src(str_to_hash, true,
		new CryptoPP::HashFilter (
			sha3_256, new CryptoPP::HexEncoder(
				new CryptoPP::StringSink(digest), false))
	);

	return digest;
}
	return encoded_c;