From ea87b30f8907ee11252433811e7a7d0c46758cca Mon Sep 17 00:00:00 2001 From: j-berman Date: Mon, 15 Nov 2021 05:23:53 -0800 Subject: Add view tags to outputs to reduce wallet scanning time Implements view tags as proposed by @UkoeHB in MRL issue https://github.com/monero-project/research-lab/issues/73 At tx construction, the sender adds a 1-byte view tag to each output. The view tag is derived from the sender-receiver shared secret. When scanning for outputs, the receiver can check the view tag for a match, in order to reduce scanning time. When the view tag does not match, the wallet avoids the more expensive EC operations when deriving the output public key using the shared secret. --- src/device/device_ledger.cpp | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'src/device/device_ledger.cpp') diff --git a/src/device/device_ledger.cpp b/src/device/device_ledger.cpp index 378d9f533..84c81bfcd 100644 --- a/src/device/device_ledger.cpp +++ b/src/device/device_ledger.cpp @@ -1527,7 +1527,8 @@ namespace hw { const bool &need_additional_txkeys, const std::vector &additional_tx_keys, std::vector &additional_tx_public_keys, std::vector &amount_keys, - crypto::public_key &out_eph_public_key) { + crypto::public_key &out_eph_public_key, + bool use_view_tags, crypto::view_tag &view_tag) { AUTO_LOCK_CMD(); #ifdef DEBUG_HWDEVICE @@ -1541,6 +1542,8 @@ namespace hw { const boost::optional change_addr_x = change_addr; const size_t output_index_x = output_index; const bool need_additional_txkeys_x = need_additional_txkeys; + const bool use_view_tags_x = use_view_tags; + const crypto::view_tag view_tag_x = view_tag; std::vector additional_tx_keys_x; for (const auto &k: additional_tx_keys) { @@ -1568,7 +1571,7 @@ namespace hw { log_hexbuffer("generate_output_ephemeral_keys: [[IN]] additional_tx_keys[oi]", additional_tx_keys_x[output_index].data, 32); } this->controle_device->generate_output_ephemeral_keys(tx_version_x, sender_account_keys_x, txkey_pub_x, tx_key_x, dst_entr_x, change_addr_x, output_index_x, need_additional_txkeys_x, additional_tx_keys_x, - additional_tx_public_keys_x, amount_keys_x, out_eph_public_key_x); + additional_tx_public_keys_x, amount_keys_x, out_eph_public_key_x, use_view_tags_x, view_tag_x); if(need_additional_txkeys_x) { log_hexbuffer("additional_tx_public_keys_x: [[OUT]] additional_tx_public_keys_x", additional_tx_public_keys_x.back().data, 32); } -- cgit v1.2.3