Electrum

2013-01-03T15:09:34Z

EagleTM: Change project website to subdomain b/c of cert warning

[[Image:Electrum_logo.png|400px]][[Image:Capture-Electrum.png|right|600px|screenshot of Electrum with its Qt gui]]

[http://ecdsa.org/electrum Electrum] is a lightweight Bitcoin client, based on a client-server protocol.
It was released on november 5, 2011.

'''Main features:'''
* Encrypted wallet: the file that contains your bitcoins is protected with a password. You are protected from thieves.
* Deterministic key generation: If you lose your wallet, you can recover it from its seed. You are protected from your own mistakes.
* Instant on: the client does not download the blockchain, it requests that information from a server. No delays, always up-to-date.
* Transactions are signed locally: Your private keys are not shared with the server. You do not have to trust the server with your money.
* Freedom and Privacy: The server does not store user accounts. You are not tied to a particular server, and the server does not need to know you.
* No scripts: Electrum does not download any script. A compromised server cannot send you arbitrary code and steal your bitcoins.
* No single point of failure: The server code is open source, anyone can run a server.
* Firewall friendly: The client does not need to open a port, it simply polls the server for updates.
* Free software: Gnu GPL v3. Anyone can audit the code.
* Written in Python. The code is short, and easy to review.
* Support for Bitcoin URIs, signed URIs and Bitcoin aliases

__TOC__

===Graphical User Interfaces===
Electrum has two GUIs: one that is based on Gtk, and a newer one based on Qt. The Qt GUI is enabled by default. To use the gtk interface, type:
<pre>
$ ./electrum -g gtk
</pre>
In addition, Electrum has a rich set of commands for the command line interface.

===Brain Wallet===

Electrum uses a type 2 deterministic key generation algorithm.
This means that all the keys are derived from a seed.

Typical seeds have 128 bits of entropy. Electrum provides mnemonic code in order to represent the seed.

Example:
*hexadecimal: 431a62f1c86555d3c45e5c4d9e10c8c7
*mnemonic: "constant forest adore false green weave stop guy fur freeze giggle clock"

You can display the seed with the command line interface. Example:
<pre>
$ ./electrum seed
Password:
431a62f1c86555d3c45e5c4d9e10c8c7 "constant forest adore false green weave stop guy fur freeze giggle clock"
</pre>

===Multiple wallets===
Electrum uses one single file per wallet. Your default wallet is located in your user account.
If you want to use another wallet, use the -w option followed by the wallet path and name:
<pre>
$ ./electrum -w /path/to/my/wallet/wallet_name
</pre>

===Export and import addresses===

You can export your private keys using the 'addresses' command:
<pre>
$ ./electrum addresses -ak
Password:
1LGoehbyeX4QBEPK1a6dhyaoMQZfqg5LKX:5JBSttEGhjEcPidSovW66Rin2EZ6LEHZ2qx8Pu2RqqNaDTBVWaF
1KcsBJa2cCxVkGJfSsg5bUeXN7Y5uLa8mP:5KiP4uiNT6KG8jnXbainCM8rDWRrgxt3PAyut4FFpDoCo1Rh6VM
1PXsn7LVXTccGhJPTUL8r2EGB4fF9kvex3:5Kj8mvBJReyk8xEBMx5cTnciQCxto5JmudiTPkqwMcd61Kf1Jqc
1KteSFTAphyByLTtUfFiVQ9s7fMVmx7c2h:5JeZ3FTbWcksLt3PKydd5U9p952UQRHwv3LoxzCA9LZ7V2bku5p
1GE5ZChAobeTEPLHDCDDKTSg3XvLkcQFjS:5JwtGEygTwF2nouhRVzW3w5DWZd1sCgxLtnd1v51wjkbUrp5sqH
12YNehfAoYTiwjTXULwaZqTCauu2D61fq6:5Jvcq19ePCXKcVun4n7US99CsrEByUK2kgxXBA3rBVBqYZjhfwD [change]
</pre>
There are two options in this example:
* option -a means: 'list all addresses'. if you don't use it, change addresses are not listed.
* option -k means: display the private keys

You can also import addresses into an electrum wallet, with the 'import' command:
<pre>
$ ./electrum import 1LGoehbyeX4QBEPK1a6dhyaoMQZfqg5LKX:5JBSttEGhjEcPidSovW66Rin2EZ6LEHZ2qx8Pu2RqqNaDTBVWaF
keypair imported
</pre>
Note that imported keys do not belong to the deterministic sequence of your wallet; if you import keys in a wallet, you must back it up!

===Offline wallet===

It is possible to create a transaction on an offline computer,
and to broadcast them from another computer, with a wallet that does not have the seed or private keys.

====How to prepare an offline wallet ====
*step 1: create a wallet on your offline computer
<pre>
[offline]$ electrum -o -w wallet create
</pre>
*step 2: extract the seed from your wallet file:
<pre>
[offline]$ electrum -o -w wallet deseed
</pre>
This will remove the seed from 'wallet', and save it to a file named 'wallet.seed'
*step 3: transfer the deseeded wallet to the online computer (for example with a usb stick)
*step 4: run electrum on the online computer; this will synchronize your wallet with the bitcoin network, and you will be able to monitor incoming transactions:
<pre>
[online]$ electrum -w wallet
</pre>

====How to send a transaction with an offline wallet====
*step 1: copy the synchronized wallet file to your offline computer, in the directory where the seed is.
*step 2: restore the seed in the wallet file:
<pre>
[offline]$ electrum -w wallet reseed
</pre>
*step 3: create the transaction
<pre>
[offline]$ electrum -w wallet mktx <recipient> <amount> > tx_file
</pre>
*step 4: with the usb stick, copy the transaction to the online computer:
*step 5: broadcast the transaction on the online computer:
<pre>
[online]$ electrum -w wallet sendtx `cat tx_file`
</pre>

=== List of commands ===

{| class="wikitable sortable"
|-
! command !! description !! syntax !! requires password !! needs to be online
|-
| addresses || show your list of addresses, optionally with private keys. || addresses [-a] [-b] [-k] || iff -k || no
|-
| balance || shows the balance of your wallet or of an address || balance [address] || no || yes
|-
| contacts || print your list of contacts || contacts || no || no
|-
| create || create a new wallet || create || no || no
|-
| deseed || Remove seed from wallet and store it to .seed file || deseed || no || no
|-
| eval || call python eval || eval <expression> || no || no
|-
| help || display the help for a command || help [command] || no || no
|-
| history || print the transaction history || history || no || yes
|-
| import || import a keypair || import <address:private_key> || yes || no
|-
| label || change the label of a transaction or address || label <label> || no || no
|-
| mktx || create a transaction and dump it || mktx [-s sourceaddr] [-c changeaddr] [-f fee] <address> <amount> || yes || no
|-
| password || update your password || password || yes || no
|-
| payto || create and broadcast a transaction || payto [-s sourceaddr] [-c changeaddr] [-f fee] <address> <amount> || yes || yes
|-
| reseed || take seed from .seed file and add it to wallet (it checks that keys are consistent). || reseed || no || no
|-
| restore || restore a wallet from seed || restore || no || yes
|-
| sendtx || broadcast a transaction || sendtx <tx> || no || yes
|-
| seed || print your seed || seed || yes || no
|-
| signmessage || sign a message (as in bitcoind) || signmessage <address> <message> || yes || no
|-
| validateaddress || check is the argument is a valid bitcoin address || validateaddress <address> || no || no
|-
| verifymessage || verify a message (as in bitcoind) || verifymessage <address> <signature> <message> || no || no
|}

==History==

Electrum was announced November 5, 2011<ref>[http://bitcointalk.org/index.php?topic=50936.0 Electrum - a new thin client]</ref>.

==See Also==

* [[Electrum/Documentation]] : General documentation of the Electrum client
* [[Electrum/Translation]]
* [[Electrum/TODO]]
* [[Thin Client Security]]

==External Links==

* [http://electrum.ecdsa.org/ Electrum] project website
* [https://github.com/spesmilo/electrum/ Electrum] project source

==References==
<references />

[[Category:Clients]]
[[Category:Open Source]]

Bitcoin Wiki - User contributions [en]

Electrum