Monero is a private, secure, untraceable, decentralised digital currency. You are your bank, you control your funds, and nobody can trace your transfers unless you allow them to do so.
**Privacy:** Monero uses a cryptographically sound system to allow you to send and receive funds without your transactions being easily revealed on the blockchain (the ledger of transactions that everyone has). This ensures that your purchases, receipts, and all transfers remain absolutely private by default.
**Security:** Using the power of a distributed peer-to-peer consensus network, every transaction on the network is cryptographically secured. Individual wallets have a 25 word mnemonic seed that is only displayed once, and can be written down to backup the wallet. Wallet files are encrypted with a passphrase to ensure they are useless if stolen.
**Untraceability:** By taking advantage of ring signatures, a special property of a certain type of cryptography, Monero is able to ensure that transactions are not only untraceable, but have an optional measure of ambiguity that ensures that transactions cannot easily be tied back to an individual user or computer.
This is the core implementation of Monero. It is open source and completely free to use without restrictions, except for those specified in the license agreement below. There are no restrictions on anyone creating an alternative implementation of Monero that uses the protocol and network in a compatible manner.
As with many development projects, the repository on Github is considered to be the "staging" area for the latest changes. Before changes are merged into that branch on the main repository, they are tested by individual developers in their own branches, submitted as a pull request, and then subsequently tested by contributors who focus on testing and code reviews. That having been said, the repository should be carefully considered before using it in a production environment, unless there is a patch in the repository for a particular show-stopping issue you are experiencing. It is generally a better idea to use a tagged release for stability.
**Anyone is welcome to contribute to Monero's codebase!** If you have a fix or code change, feel free to submit is as a pull request directly to the "master" branch. In cases where the change is relatively small or does not affect other parts of the codebase it may be merged in immediately by any one of the collaborators. On the other hand, if the change is particularly large or complex, it is expected that it will be discussed at length either well in advance of the pull request being submitted, or even directly on the pull request.
The Monero donation address is: `44AFFq5kSiGBoZ4NMDwYtN18obc8AemS33DBLWs3H7otXft3XjrpDtQGv7SqSsaBYBb98uNbr2VBBEt7f2wfn3RVGQBEP3A` (viewkey: `f359631075708155cc3d92a32b75a7d02a5dcf27756707b47a2b31b21c389501`)
There are also several mining pools that kindly donate a portion of their fees, [a list of them can be found on our Bitcointalk post](https://bitcointalk.org/index.php?topic=583449.0).
Monero uses a fixed-schedule hard fork mechanism to implement new features. This means that users of Monero (end users and service providers) need to run current versions and update their software on a regular schedule. Here is the current schedule, versions, and compatibility.
build the library binary manually. This can be done with the following command ```sudo apt-get install libgtest-dev && cd /usr/src/gtest && sudo cmake . && sudo make && sudo mv libg* /usr/lib/ ```
* Install the latest version of boost (this may first require invoking `apt-get remove --purge libboost*` to remove a previous version if you're not using a clean install):
* Edit the properties for the `MSYS2 Shell` shortcut changing "msys2_shell.bat" to "msys2_shell.cmd -mingw64" for 64-bit builds or "msys2_shell.cmd -mingw32" for 32-bit builds
The project can be built from scratch by following instructions for Linux above. If you are running monero in a jail you need to add the flag: `allow.sysvipc=1` to your jail configuration, otherwise lmdb will throw the error message: `Failed to open lmdb environment: Function not implemented`.
The Boost package has a bug that will prevent librpc.a from building correctly. In order to fix this, you will have to Build boost yourself from scratch. Follow the directions here (under "Building Boost"):
By default, in either dynamically or statically linked builds, binaries target the specific host processor on which the build happens and are not portable to other processors. Portable binaries can be built using the following targets:
* ```make release-static-64``` builds binaries on Linux on x86_64 portable across POSIX systems on x86_64 processors
* ```make release-static-32``` builds binaries on Linux on x86_64 or i686 portable across POSIX systems on i686 processors
While Monero isn't made to integrate with Tor, it can be used wrapped with torsocks, if you add --p2p-bind-ip 127.0.0.1 to the monerod command line. You also want to set DNS requests to go over TCP, so they'll be routed through Tor, by setting DNS_PUBLIC=tcp. You may also disable IGD (UPnP port forwarding negotiation), which is pointless with Tor. To allow local connections from the wallet, you might have to add TORSOCKS_ALLOW_INBOUND=1, some OSes need it and some don't. Example:
TAILS ships with a very restrictive set of firewall rules. Therefore, you need to add a rule to allow this connection too, in addition to telling torsocks to allow inbound connections. Full example:
While monerod and monero-wallet-cli do not use readline directly, most of the functionality can be obtained by running them via rlwrap. This allows command recall, edit capabilities, etc. It does not give autocompletion without an extra completion file, however. To use rlwrap, simply prepend `rlwrap` to the command line, eg:
Note: rlwrap will save things like your seed and private keys, if you supply them on prompt. You may want to not use rlwrap when you use simplewallet to restore from seed, etc.
This section contains general instructions for debugging failed installs or problems encountered with Monero. First ensure you are running the latest version built from the github repo.
## Obtaining Stack Traces and Core Dumps on Unix Systems
We generally use the tool `gdb` (GNU debugger) to provide stack trace functionality, and `ulimit` to provide core dumps in builds which crash or segfault.
* To use gdb in order to obtain a stack trace for a build that has stalled:
Run the build.
Once it stalls, enter the following command:
```
gdb /path/to/monerod `pidof monerod`
```
Type `thread apply all bt` within gdb in order to obtain the stack trace
* If however the core dumps or segfaults:
Enter `ulimit -c unlimited` on the command line to enable unlimited filesizes for core dumps
Run the build.
When it terminates with an output along the lines of "Segmentation fault (core dumped)", there should be a core dump file in the same directory as monerod.
You can now analyse this core dump with `gdb` as follows:
`gdb /path/to/monerod /path/to/dumpfile`
Print the stack trace with `bt`
* To run monero within gdb:
Type `gdb /path/to/monerod`
Pass command-line options with `--args` followed by the relevant arguments
Type `run` to run monerod
## Analysing Memory Corruption
We use the tool `valgrind` for this.
Run with `valgrind /path/to/monerod`. It will be slow.
Instructions for debugging suspected blockchain corruption as per @HYC
There is an `mdb_stat` command in the LMDB source that can print statistics about the database but it's not routinely built. This can be built with the following command:
`cd ~/monero/external/db_drivers/liblmdb && make`
The output of `mdb_stat -ea <path to blockchain dir>` will indicate inconsistencies in the blocks, block_heights and block_info table.
The output of `mdb_dump -s blocks <path to blockchain dir>` and `mdb_dump -s block_info <path to blockchain dir>` is useful for indicating whether blocks and block_info contain the same keys.
These records are dumped as hex data, where the first line is the key and the second line is the data.
