Read more about k-anonymity [here](https://en.wikipedia.org/wiki/K-anonymity). We implement this feature in the monero daemon for transactions
by providing a "Txid Template", which is simply a txid with all but `num_matching_bits` bits zeroed out, and the number `num_matching_bits`. We add an operation to `BlockchainLMDB` called
`get_txids_loose` which takes a txid template and returns all txids in the database (chain and mempool) that satisfy that template. Thus, a client can
ask about a specific transaction from a daemon without revealing the exact transaction they are inquiring about. The client can control the statistical
chance that other TXIDs (besides the one in question) match the txid template sent to the daemon up to a power of 2. For example, if a client sets their `num_matching_bits`
to 5, then statistically any txid has a 1/(2^5) chance to match. With `num_matching_bits`=10, there is a 1/(2^10) chance, so on and so forth.
Co-authored-by: ACK-J <60232273+ACK-J@users.noreply.github.com>
- Straight-forward call interface: `void rx_slow_hash(const char *seedhash, const void *data, size_t length, char *result_hash)`
- Consensus chain seed hash is now updated by calling `rx_set_main_seedhash` whenever a block is added/removed or a reorg happens
- `rx_slow_hash` will compute correct hash no matter if `rx_set_main_seedhash` was called or not (the only difference is performance)
- New environment variable `MONERO_RANDOMX_FULL_MEM` to force use the full dataset for PoW verification (faster block verification)
- When dataset is used for PoW verification, dataset updates don't stall other threads (verification is done in light mode then)
- When mining is running, PoW checks now also use dataset for faster verification
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.
It avoids dividing by 8 when deserializing a tx, which is a slow
operation, and multiplies by 8 when verifying and extracing the
amount, which is much faster as well as less frequent
In this repo, `boost::interprocess` was being used soley to make `uint32_t` operations atomic. So I replaced each instance of
`boost::interprocess::ipcdetail::atomic(...)32` with `std::atomic` methods. I replaced member declarations as applicable. For example,
when I needed to change a `volatile uint32_t` into a `std::atomic<uint32_t>`. Sometimes, a member was being used a boolean flag, so
I replaced it with `std::atomic<bool>`.
You may notice that I didn't touch `levin_client_async.h`. That is because this file is entirely unused and will be deleted in PR monero-project#8211.
Additional changes from review:
* Make some local variables const
* Change postfix operators to prefix operators where value was not need
Adds the following:
- "get_miner_data" to RPC API
- "json-miner-data" to ZeroMQ subscriber contexts
Both provide the necessary data to create a custom block template. They are used by p2pool.
Data provided:
- major fork version
- current height
- previous block id
- RandomX seed hash
- network difficulty
- median block weight
- coins mined by the network so far
- mineable mempool transactions
There are quite a few variables in the code that are no longer
(or perhaps never were) in use. These were discovered by enabling
compiler warnings for unused variables and cleaning them up.
In most cases where the unused variables were the result
of a function call the call was left but the variable
assignment removed, unless it was obvious that it was
a simple getter with no side effects.
