Bitcoin Wiki - User contributions [en]

Tor

2012-01-05T20:03:54Z

Notawake: Fixed broken bitcoin forum link

'''Tor''' is a distributed 'onion' network, that makes it more difficult for an adversary to track any one peer on the network. Tor also is very useful to access the 'uncensored' internet in countries such as China and Iran. Preserving privacy means not only hiding the content of messages, but also hiding who is talking to whom (traffic analysis). Tor provides anonymous connections that are strongly resistant to both eavesdropping and traffic analysis.

Bitcoin can run easily on the Tor network.

=Tor installation & use=
''todo explain: onion routing (how tor network helps to anonymize), encryption used, exit nodes, routers'' 

Please follow the instructions provided with installation files and read the [http://www.torproject.org/download/download.html.en#warning list of warnings]. ''Tor doesn't magically anonymize all your traffic just because you install it.'' 
Down the page you can find examples how to configure applications to use Tor to anonymize the origin of your traffic. 
[http://www.torproject.org/docs/tor-doc-windows.html.en This] is a detailed installation guide for Windows. Before you setup Bitcoin or mIRC to use Tor, please install Tor and start in. 
[[{{ns:file}}:20110109-tor-running.png]] On the taskbar of your compute you'll see a small green onion when Tor is running.
[[{{ns:file}}:20110109-bitcoin-mirc-vidalia.png]]

=GUI=
Once you have your Tor client up & running, you can configure your Bitcoin client to use it. 
Select in menu Settings -> Options 
[[{{ns:file}}:20110108-btc-options.png]] 

Check "Connect through socks 4 proxy" with the address 127.0.0.1 and port 9050 (the Tor default port number) 
[[{{ns:file}}:20110108-btc-client-tor-as-proxy.png]] 
Configuring an application to use Tor is also called to torify it.
(needs a brief howto here)

''the note about bitcoin-otc promote on a more appropriate place in this page? reference to trading and IRC''
Conducting business using [[bitcoin-otc]] can be done more anonymously when directly connected to a Freenode IRC hidden service.

=bitcoind=

Run bitcoind with -proxy=127.0.0.1:9050 (or whatever your SocksPort is).

bitcoind will detect that you are using a proxy on 9050 and will force the "nolisten" flag. If you are not running tor on 9050, you need to set "nolisten" manually otherwise you will listen on your public IP and possibly reveal that you are running a node.

=Hidden services=
These services are running within the tor network. You can connect to them for example using the -connect= parameter to bitcoind. Note that you do not need to use them - tor can also anonymize your normal internet traffic, including bitcoin connections. There are some technical reasons why hidden services may be beneficial, see the tor documentation if you're really interested.

Services are listed at [[Fallback_Nodes#Tor_network]] along with instructions for using them.

=Pooled Mining=

Some mining pools are available as a hidden service on the tor network. Any pool can be reached over tor. The general methodology here is to tell your mining client to use your local Tor proxy. This is client specific but there are some helpful hints.

==Linux / BSD==

Any client can have its traffic routed via Tor by using the torify command and invoking the miner with that. Another method is to set the http_proxy environment variable as some miners use libraries which support that.

==Windows / OS X==

It is possible to set the http_proxy environment variable as some miners use libraries which support that.

=mIRC=

mIRC is a popular IRC client. This is a guide how to connect to Freenode IRC using Tor + SASL + mIRC. 
==Register your nick with freenode nickserv ==
Freenode only allows SASL authenticated users to connect to the onion IRC server. SASL authentication works only with a registered nickname. 
Connect to Freenode IRC without using tor & execute 
/msg nickserv register <password> <email> 
 
You will see something like this 
-NickServ- An email containing nickname activation instructions has been sent to <email> 
-NickServ- If you do not complete registration within one day, your nickname will expire. 
 
To finish your nick registration go the provided email and copy/paste the command from e-mail to irc. 

==Add SASL support to your mIRC installation ==
Download the SASL.dll and sasl.mrc files and copy them to your mIRC installation directory 
Load sasl.mrc script (Alt + R to open script editor, Ctrl + L to load file, browse to sasl.mrc, press OK or "save & exit"). 
[[{{ns:file}}:20110109-sasl-script-loaded.png]] 
Type /dialog -m SASL.main SASL.main to open the SASL connection manager. 
[[{{ns:file}}:20110109-sasl-dialog.png]] 
Add Freenode entry. 
[[{{ns:file}}:20110109-sasl-manager.png]][[{{ns:file}}:20110109-sasl-manager-network.png]] 
Network is Freenode. 
Username and NS Password must match your nickserv reservation. 
Auth Type can be PLAIN 

==setup mIRC to use Tor ==
Add the entry for Freenode onion IRC server 
[[{{ns:file}}:20110109-onion-irc-add.png]] 
Configure mIRC to use a Proxy (your local Tor proxy) 
[[{{ns:file}}:20110109-mirc-proxy.png]] 
 
Now you should be able to connect. 
[https://www.bitcointalk.org/index.php?topic=2602 Bitcoin forum where this topic is discussed]

=How Tor works=
Unlike Freenet, I2P, etc., Tor's security is very well-defined. While weaknesses do exist (described below), they have been known since Tor was created, and new weaknesses of significance are not expected.

Tor sends TCP packets over 3 (normal) or 7 (hidden services) Tor relays. This is why it is so slow: your packet might have to go through 100 computers (counting Internet routers) before it reaches its destination. Tor uses multiple ''layers'' of encryption that are ''pulled away'' for each node. Hence the name '''T'''he '''O'''nion '''R'''outer, which is always capitalized as '''Tor''', and never TOR or t.o.r.

Say that I want to connect to bitcoin.org through Tor. I first select three Tor relays that I know about. Then, I send a message to my ISP that looks like this:
Send to this IP: <IP of Relay1>
<Encrypted data for Relay1>
When Relay1 receives this, he decrypts the payload using his private key. The payload contains this:
Send to this Tor node: <Relay2>
<Encrypted data for Relay2>
Relay2 decrypts his payload:
Send to this Tor node: <Relay3>
<Encrypted data for Relay3>
Relay3 receives the real TCP payload, which he sends to the destination:
Send to this IP: <IP of destination>
<Unencrypted payload>
The payload is not and can not be further encrypted by Tor. However, if the protocol itself uses encryption (HTTPS, SSH, etc.), the data will be encrypted. This means that the last node (the ''exit node'') can see everything you do on HTTP sites, and can steal your passwords if they are transmitted unencrypted. Many people become exit nodes just so they can view this information -- Tor is much more dangerous than open WiFi for snooping!

The encryption arrangement described above ensures that no single Tor node knows both the sender and the destination. Relay1 and your ISP know that you are using Tor and sending a packet at a certain time, but they don't know what you're sending or who you're sending to. Relay3 knows exactly what you're sending, but he can't determine who is sending it because Relay2 and Relay1 are blocking him. All three relays need to work together in order to conclusively connect the sender and the destination.

However, Tor is weak to a ''timing attack'' that allows only two participants in certain positions to determine the sender with high accuracy. Consider this Tor connection:
Sender <-> S-ISP <-> Relay1 <-> Relay2 <-> Relay3 <-> D-ISP <-> Destination
If the sender's ISP (S-ISP) and the destination are working together, they can record the size and times of packets sent and received. Over a large number of packets, they can determine with very high accuracy that the sender is, in fact, the person sending packets to the destination. This requires active surveillance or detailed logging by both sides. Relay1 can also perform the same role as S-ISP.

Additionally, more configurations are possible if the underlying connection is not encrypted (normal HTTP, for example):
*S-ISP & Relay3
*Relay1 & Relay3
*S-ISP & D-ISP
*Relay1 & D-ISP
This second set can always see that the sender is connected to the destination, but they can only see what the sender is doing on the site if the connection is not encrypted. (Pathnames are encrypted in HTTPS.)

Because the first relay (the ''entry node'') is a weak point in the connection, Tor takes certain defensive measures. When you first start Tor, it chooses three ''entry guards'' that don't change for the entire time that you run Tor. You will always use one of those three unless one goes down. If all of those nodes are safe and your ISP is safe, then you are OK.

These timing attacks are of special importance to Bitcoin because anyone can be the "destination" in a connection. Packets are broadcast to every peer in the Bitcoin network. This might allow your ISP alone to associate your transactions to you without much difficulty. However, a timing attack relies on receiving at least several dozen packets from the sender, so the "destination" might actually have to be one of your direct Bitcoin peers. It's not too difficult to flood the Bitcoin network with peers, though. Because of this attack, it is wise to use an [[EWallet]] instead of the Bitcoin client when using Tor.

To discover Tor relays, Tor uses a centralized directory server model. There are nine authoritative directory servers. To become a relay, you register with one of these. The directory servers share their data and produce a ''network status consensus'' document every so often containing all Tor nodes. Tor clients don't connect directly to the authoritative directory servers -- they connect to one of many ''directory mirrors'', which have a copy of the network status consensus. Since there is no peer-to-peer bootstrap mechanism in Tor, the entire network can be destroyed if half of the authoritative directory servers are destroyed, and the entire network can be subverted if half of the authoritative directory servers become evil.

Hidden services allow both the sender and destination to remain anonymous. A hidden service connection is made like this:
*The destination tells several Tor relays to act as ''introduction points'' for the hidden service. The destination stays connected to all of these introduction points through a regular three-node Tor circuit.
*The destination registers these introduction points on a Tor DHT. The introduction points are associated with the first 16 characters of an encoded SHA-1 hash of the destination's key. This is the information in .onion addresses. The use of SHA-1 is a possible weakness.
*The sender creates a four-node Tor circuit. The fourth node is called the ''rendezvous point''.
*The sender searches the DHT for the introduction points of the desired hidden service. The sender connects to one through a regular three-node Tor circuit and, through the introduction point, tells the destination about the rendezvous point he has chosen.
*The destination connects to the rendezvous point over a three-node Tor circuit. The sender and destination are now in contact over a seven-node connection.

For clients, hidden services are more secure than encrypted Tor HTTPS connections because:
*If the destination remains anonymous, they are less likely to become controlled by an evil party.
*The destination's ISP isn't involved as they are in the HTTPS case. Only these configurations are possible for a timing attack:
**S-ISP & Destination
**Relay1 & Destination

Running a hidden service is more dangerous, however. A simple intersection attack can be performed by the hidden service's ISP alone:
*Your Internet service is cut off.
*If the hidden service went down at that exact moment, you are unmasked.
The same sort of timing attacks as above are also possible.

See the [http://www.usenix.org/events/sec04/tech/full_papers/dingledine/dingledine_html/index.html Tor design paper] for more info.

=External Tor Hidden Services=

* [http://vms43o4cqysakvyb.onion Bitcoin 4 Cash] ([[Bitcoin 4 Cash|info]])
* [irc://p4fsi4ockecnea7l.onion Freenode hidden service]

=External links=

* [http://tor.eff.org/ Tor project]
* [http://www.torproject.org/docs/tor-doc-windows.html.en Tor installation guide - Windows]
* [https://trac.torproject.org/projects/tor/wiki/TheOnionRouter/TorFAQ Tor FAQ]
* [http://www.torproject.org/about/overview.html.en how Tor works - overview]
* [http://freenode.net/irc_servers.shtml#tor Freenode over Tor info]
* [http://wiki.honk-honk.org/wiki/SaslServ#mIRC howto enable SASL in mIRC]
* [http://honk-honk.org/SASL/SASL.dll SASL.dll library for mIRC]
* [http://honk-honk.org/SASL/sasl.mrc sasl script for mIRC]
* [http://freenode.net/sasl/ Freenode resources on SASL]

Abe

2011-11-27T02:38:52Z

Notawake: Fixed broken bitcoin forum link

[[File:penny-abe-160.png|thumb|160px|Abe]]

'''Abe''' is a free, open-source [[block chain browser]] released by [[User:JohnTobey253|John Tobey]] under the [[wikipedia:Affero General Public License|Affero General Public License]].

Written in [[wikipedia:Python (programming language)|Python]] and portable [[wikipedia:SQL|SQL]],<ref>https://bitcointalk.org/index.php?topic=16141.0</ref> Abe draws inspiration from [[Bitcoin Block Explorer]] and seeks some level of compatibility with it but uses a completely new implementation.<ref>https://raw.github.com/jtobey/bitcoin-abe/master/README.md</ref>

==See Also==

* [[Block chain browser]]

== External Links ==

* [http://abe.john-edwin-tobey.org/ Demonstration site]
* [https://bitcointalk.org/index.php?topic=16141.0 Project announcement]
* [https://github.com/jtobey/bitcoin-abe Project on Github]

==References==
<references />

[[Category:Block chain browsers]]
[[Category:Free Software]]
[[Category:Open Source]]

Gribble

2011-11-27T02:37:51Z

Notawake: Fixed broken bitcoin forum link

[http://gribble.sourceforge.net/ gribble] is a modified Supybot IRC bot, carrying some useful bitcoin-related commands and factoids. The bot's command sequence is ';;', to issue any command just start a line with two semicolons. You can also issue inline commands with two commas.

It is present on #bitcoin-dev (bitcoin information queries), #bitcoin-market (real time streaming quotes from bitcoinmarket.com and mtgox.com), #bitcoin-otc (facilitate over-the-counter trading, with the OTC order book and OTC web of trust). You can also PM commands to gribble and it will PM back.

==General Info==

To get help on any command, try 'help <command>', to get a list of bitcoin-related commands, run 'apropos bc', and to get a list of factoids, run command 'facts', and click on the link supplied.

==List of commands==

===Mining/network/hashrate stats===

* '''bc,blocks''' - show the current number of blocks in the bitcoin block chain
* '''bc,calc''' - given a hash rate in Khps, calculate the expected average time to generate a block, at current difficulty. For example, to see the average time for 1000 Khps, run 'bc,calc 1000'.
* '''bc,calcd''' - given a hash rate in Khps, and a difficulty level, calculate the expected average time to generate a block at that difficulty. For example, to see the average time for 1000 Khps at difficulty 1, run 'bc,calc 1000 1'.
* '''bc,diff''' - show the current generation difficulty
* '''bc,diffchange''' - show estimated percent change in difficulty
* '''bc,estimate''' - show the estimate of the next difficulty<ref>[https://bitcointalk.org/index.php?topic=3247.0 Estimate is usually wildly inaccurate for 100-200 blocks after a difficulty change due to insufficient sample size.]</ref>
* '''bc,gen''' - given the hash rate in Khps, calculate expected BTC generation per day and per hour, at current difficulty.
* '''bc,gend''' - given the hash rate in Khps, and a difficulty level, calculate expected BTC generation per day and per hour at that difficulty.
* '''bc,hextarget''' - show the current difficulty target in hex.
* '''bc,nethash''' - current 3-day estimate of network hash power, in Ghps.
* '''bc,nexttarget''' - show the block at which the next difficulty change will take place
* '''bc,interval''' - show the average time between blocks, over the past 1000 blocks. If given optional integer argument, use that many blocks for the estimate.
* '''bc,prob''' - show the probability of getting at least one block at given Khps, in a given time period. E.g., to see probability of getting a block at 1000 Khps, in 2 years and 1 week, try 'bc,prob 1000 2y 1w'. Time takes input in years, weeks, days, hours, minutes, and seconds.
* '''bc,probd''' - show the probability of getting at least one block at given Khps, given difficulty, in a given time period. Same as '''bc,prob''' but supply a difficulty after the hash rate. E.g., 'bc,probd 10000000 600000 1w 2d'
* '''bc,spotestimate''' - current 3-day estimate of network power, in terms of difficulty.
* '''bc,stats''' - show some statistics about the block chain - number of blocks, difficulty, estimated next difficulty target, time to next difficulty
* '''bc,timetonext''' - show estimated time to reach the next difficulty target
* '''bc,totalbc''' - show total number of bitcoins in existence.

Big kudos goes out to theymos for providing a web interface to [http://blockexplorer.com/q/ real time statistics about the bitcoin block chain].

===Markets and exchange rates===

* '''bc,bcm''' - show the market snapshot from bitcoinmarket.com
* '''bc,mtgox''' - show the market snapshot for mtgox.com
* '''bc,avgprc''' - show average 24h, 7d, and 30d trading prices of BTC in various currencies.
* '''bc,24hprc''' - show average 24h price of BTC in USD.
* '''bc,convert''' - convert bitcoin price, based on MtGox last, to currency you specify. e.g., try 'bc,convert eur' for euros.
* '''bc,fx''' - show various currency exchange rates
* '''bc,xau''' - show price of gold in BTC
* '''ticker''' - show pretty-printed mtgox ticker. Takes optional argument of '--bid', '--ask', '--last', '--high', or '--low', to show just that numeric value (useful for command nesting in calculations)
* '''bids''' - given a numeric argument, shows how many total btc are being demanded on MtGox at or over the given price. If optional '--under' argument given, looks under the price.
* '''asks''' - given a numeric argument, shows how many total btc are being offered on MtGox at or below given price. If optional '--over' argument given, looks over the price.

===Mining pool statistics===

* '''bc,slushpool''' - show the mining hash rate of the [http://mining.bitcoin.cz slush mining pool], in Khps.
* '''bc,eligius''' - show the mining hash rate of the Eligius mining pool, in Khps
* '''bc,swepool''' - show the mining hash rate of the Swepool mining pool, in Khps
* '''bc,btcguild''' - show the mining hash rate of the Btcguild mining pool, in Khps
* '''bc,deepbit''' - show the mining hash rate of the Deepbit mining pool, in Khps

===Other===

* '''bc,help''' - show list of 'bc,' commands - same as 'apropos bc'.
* '''bc,wiki''' - fetch a link to a page in this wiki, based on a search string. For example, to see a link to this page, try 'bc,wiki gribble'.

===bitcoin-otc related info===

* See [http://wiki.bitcoin-otc.com/wiki/Using_bitcoin-otc OTC guide] about using the order book
* See [http://wiki.bitcoin-otc.com/wiki/GPG_authentication OTC GPG guide] about using the gpg authentication system
* See [http://wiki.bitcoin-otc.com/wiki/OTC_Rating_System Web of Trust guide] about using the rating system/web of trust

===General commands===

The above list is specifically for bitcoin-related commands. See [http://sourceforge.net/apps/mediawiki/gribble/index.php?title=Using_Gribble_on_Sourceforge this page] for list and help of most commonly used non-bitcoin-related gribble commands. You can find more helpful info on the [http://gribble.sourceforge.net/ gribble] project page, or by exploring the bot with 'list' and 'help' commands.

==References==
<references />

==Factoids==

* [http://gribble.dreamhosters.com/viewfactoids.php?db=%23bitcoin-dev factoids for #bitcoin-dev channel]
* [http://gribble.dreamhosters.com/viewfactoids.php?db=%23bitcoin-otc factoids for #bitcoin-otc channel]

==Examples==

<me> ;;bc,blocks
<gribble> 96009

<me> Check out the current difficulty! ,,bc,diff
<gribble> 8078.19525793

<me> Here is a list of all gribble bitcoin commands: ,,(apropos bc)
<gribble> Alias bc,bcm, Alias bc,blocks, Alias bc,btcex, Alias bc,calc, Alias bc,diff, Alias bc,estimate, Alias bc,mtgox, Alias bc,nexttarget, Alias bc,stats, Alias bc,timetonext, and Alias bc,totalbc

<me> ;;list
<gribble> Admin, Alias, Anonymous, [...]

<me> ;;list Alias
<gribble> ?, about, add, bc,bcm [...], sfwikisearch, sl, slap, smack, [...]

<me> ;;sl bitcoin
<gribble> http://www.bitcoin.org/ | Bitcoin is a peer-to-peer digital currency. Peer-to-peer (P2P) means [...]

<me> Some commands have more than one argument. Surround with parens.
<me> e.g., Is your wallet safe? ,,(bc,wiki secure wallet)
<gribble> https://en.bitcoin.it/wiki/Securing_your_wallet | Apr 6, 2011 ... However a few [...]

<me> ;;calc 25 USD in EUR
<gribble> 25 US dollars = 17.2248 euros

===list of commands===

?, about, action, add, alert, alias, announce, announce add, announce list, announce remove, any, aol, apply, apropos, asks, at, auth, author, azn, ban add 
ban list, ban remove, base, bashorg, bc,24hprc, bc,avgprc, bc,bcm, bc,blocks, bc,btceur, bc,btcgbp, bc,btcguild, bc,btcrub, bc,calc, bc,calcd, bc,channels, bc,convert, bc,deepbit, bc,diff, bc,diffchange, bc,eligius, bc,estimate, bc,fx, bc,gen, bc,gend, bc,help, bc,hextarget, bc,interval, bc,mtgox, bc,mtgoxask, bc,mtgoxbid, bc,mtgoxlast, bc,nethash, bc,nexttarget, bc,price, bc,prob, bc,probd, bc,slushpool, bc,spotestimate, bc,stats, bc,swepool, bc,timetonext, bc,totalbc, bc,wiki, bc,xau, bids, binary, blockmonitor, bold, book, bot, botsnack, boturl, botweb, buy 
cache, calc, call, cand, capabilities, capability add, capability list, capability remove, capability set, capability setdefault, capability unset, capitalize, ceq, change, changekey, changename, channel, channeldb, channels, channelstats, check, cheer, chr, cif, clearq, cmd, coin, collect, color, colorize, command, commands, concat, config, configure, connect, contributors, convert, cor, countargs, cpu, crypt, ctell, ctime, cut, cxor, cycle 
decode, default, defaultcapability, defaultplugin, dehalfop, deleteuser, deop, devoice, dice, dict, dictionaries, direct, disable, disconnect, dns, do, doctype, driver 
eauth, ebay, echo, ed, eightball, elapsed, enable, encode, environ, eregister, errno, eval, everify, exec, exn, export 
factlist, facts, feed, fetch, field, fight, fit, flush, forget, format, fortune 
ge, get, getprefix, getrating, gettrust, ghost, give, giveme, giveout, gnu, google, gribble, gt 
h, halfop, headers, hebrew, help, hexip, hexlify, histsearch, hostmask, hostmask add, hostmask list, hostmask remove, hug 
icalc, ident, identify, ignore, ignore add, ignore list, ignore remove, info, insert, invite, ircquote, isitdown 
jeffk, join 
kban, key, kick 
last, latency, le, learn, leet, len, levenshtein, limit, list, lithp, load, lobotomy add, lobotomy list, lobotomy remove, lock, logmark, lower, ls, lt, lucky 
match, md5, mode, moderate, monologue, more, morse, mp 
names, nceq, ne, net, netcraft, networks, nge, ngt, nick, nicks, nle, nlt, nne, notes, notice 
oobhresponse, op, ord, otc, outfilter 
part, password, pet, petuser, pgp, phonebook, pid, ping, plugin, plugins, pong, private, processes, progstats 
quit 
rainbow, random, rank, rate, rated, re, reconnect, redo, refresh, register, reload, remove, rename, reorder, repeat, replace, replies, reply, repr, restore, reverse, rot13, roulette, rpn, rss 
sample, say, scramble, search, seconds, seen, sell, sendquote, separator, server, set, set password, set secure, settrace, sfideasearch, sflaconica, sfticketsearch, sfuserpage, sfwikisearch, sha, show, shrink, shuffle, simpleeval, since, size, sl, slap, slogan, smack, soundex, source, spell, spellit, squish, start, stats, status, stop, stripcolor, success, sudo, suicide, supa1337, swap, synonym 
targetproject, tell, texthelp, threads, ticker, time, title, tn,blocks, tn,diff, topic, translate, trustinfo 
ud, unauth, unban, unbinary, underline, undo, undup, unhexlify, unidentify, units, uniud, unload, unlock, unmoderate, unmorse, unrate, unregister, unrename, unsettrace, until, upkeep, upper, uptime, urlquote, urlunquote, user, username 
vacuum, verify, version, view, voice 
whatis, whoami, whois, wk, wp, wtf 
xor 
yt