Bitcoin Wiki - User contributions [en]

Hardware wallet

2015-08-07T15:48:55Z

Muhammed Zakir:

A '''hardware wallet''' is a device that stores a part of a user's [[wallet]] securely in mostly-offline hardware. They have major advantages over other wallet types:

* the key is often stored in a protected area of a microcontroller, and cannot be transferred out of the device in plaintext
* immune to computer viruses that steal from software wallets
* can be used securely and interactively, as opposed to a [[paper wallet]] which must be imported to software at some point
* much of the time, the software is open source, allowing a user to validate the entire operation of the device

This page is an attempt to summarize all the known developments of hardware wallets that can use Bitcoin as part of their operation.

== Purchasable hardware wallets (ordered chronologically) ==

=== Pi Wallet - cold storage ===
[[File:Piwallet.jpeg|300px|thumb|left|Pi-Wallet]]
[http://www.pi-wallet.com/ Pi-Wallet Shop]

[http://www.pi-wallet.com/pages/what-is-pi-wallet Further informations about Pi-Wallet]

The Pi-Wallet is comparable to an offline Notebook.

However it combines all features of the Armory bitcoin client (e.g. offline transaction signing) with the advantages of a tiny computer.

To sign offline-transaction you will need an (unused) USB stick.

 

=== [[TREZOR]] The Bitcoin Safe ===
[http://bitcointrezor.com BitcoinTrezor.com]

[[File:Trezor-tx.jpg|300px|thumb|left|Confirming the transaction with TREZOR]]

[[TREZOR]] is a secure bitcoin storage and a transaction signing tool. The private keys are generated by the device and never leave it thus they cannot be accessed by a malware.

It uses a deterministic wallet structure which means it can hold an unlimited number of keys (BIP32/BIP44). A recovery seed is generated when the device is initialized. In case TREZOR gets lost or stolen, all its contents can be recovered using this seed (private keys, bitcoin balance and transaction history) into a new device or another BIP39/BIP44 compatible wallet.

TREZOR also introduced a unique way of PIN entering preventing keyloggers from recording it even when entered on a compromised computer. An encryption passphrase can be set on top of the PIN protection. More passphrases can be used for plausible deniability.

[http://BuyTrezor.com E-shop BuyTrezor.com] | [http://doc.satoshilabs.com/ TREZOR Documentation]

 

=== BTChip HW.1 - USB Smartcard Hardware Wallet ===
[https://www.hardwarewallet.com HW.1 Home Page]

[[File:Btchip_dongle.jpg|220px|thumb|left|HW.1 inserted in a laptop]]

HW.1 is an implementation of a deterministic (BIP 32) Hardware Wallet on a USB smartcard.

It is typically used as a blind secure device for multi signature transactions - holding a set of derived private keys and signing transactions without requiring user confirmation.

Power users can rely on it to confirm all transactions with a second factor scheme turning the dongle into a keyboard typing what the user is supposed to have signed, as a protection against malware.

It is also possible to customize HW.1 for more specfic needs, such as creating a prepaid card without revealing the deterministic seed before it is received by the user, or securing bitcoin transactions on a server.

[https://buy.hardwarewallet.com E-shop] | [https://btchip.github.io/btchip-doc/bitcoin-technical.html Technical Documentation]

 

=== Ledger Wallet - USB Smartcard Hardware Wallet ===

[[File:ledger_wallet_photo.jpg|300px|thumb|left|Ledger Wallet USB]]

Ledger Wallet protects your Bitcoin data within a smartcard. Its micro-processor certified against all types of attacks (both physical and logical), and has been used in the banking industry for decades (think credit card chips).

The Ledger Wallet connects to your computer through the USB port and will do all the Bitcoin cryptographic heavy lifting such as signing transactions inside its secure environment. You can therefore use your Bitcoin account with maximum trust, even on an insecure or compromised computer.

It is compatible with Electrum 2.0 for power users, or with the Ledger Wallet Chrome application which provides an easy onboarding as well as a seamless user experience.

[https://www.ledgerwallet.com Ledger Wallet Home] | [https://github.com/LedgerHQ Source and specifications]

 

=== [[BWALLET]] TREZOR clone ===
[http://mybwallet.com MyBWALLET.com]

[[File:BWALLET_Trezor_Clone.jpeg|200px|thumb|left|Chinese clone of Trezor]]

[[BWALLET]] is a clone of Trezor by a Chinese company.
Trezor code is open source and this device operates like a Trezor.
However, this product has been [https://www.reddit.com/r/Bitcoin/comments/2tyier/bwallet_review_by_trezor_developer/ reviewed by Merek aka Slush(Trezor developer)] and he has found some problems which makes this device 100% compatible, for example it doesn't work with [http://mytrezor.com myTREZOR.com] website and it does not work with Trezor official firmware.

[http://www.coincola.com/shops/54c1fc24963d3759182b2c7f?locale=en Buy BWALLET]

 

== Not purchasable hardware wallets ==

=== BitcoinCard Megion Technologies-Card based wallet ===
[[File:Bitcoincard-medley-large.jpg|400px|thumb|left|Bitcoin Card]]
[http://www.bitcoincard.org/ Bitcoincard Home Page]

[http://blog.bitinstant.com/blog/2012/6/19/our-discovery-in-vienna-the-bitcoin-card.html Excellent review by evoorhees]

Incorporates a e-paper display, keypad, and radio (custom ISM band protocol.) Unfortunately it is fairly limited in terms of transaction I/O, requiring a radio gateway or another bitcoincard wherever funds need to be transferred.

 

=== BitSafe - allten/someone42's hardware wallet ===
[[File:Bitsafe-wallet-sizecompare.jpg|200px|thumb|left|Bitsafe wallet]]
[https://bitcointalk.org/index.php?topic=127587.0 BitSafe Hardware Wallet Development - BOM Ready - 50 kits being prepared]

Signing transactions only, requires USB host software for transactions & USB power. Has a OLED display and Confirm/Cancel buttons. Evolved out of someone42's prototype below, and has significant contributions from someone42 as well.
 
=== someone42's original prototype ===
[[File:Someone42-wallet-prototype.jpg|300px|thumb|left|someone42's original prototype]]
[https://bitcointalk.org/index.php?topic=78614.0 Hardware Bitcoin wallet - a minimal Bitcoin wallet for embedded devices]

Signing transactions only, requires USB host software for transactions & USB power. All work is rolled into the above BitSafe wallet currently.
 
=== Other/Defunct but with good discussion: ===
* natman3400's BitClip Jun 2011 [https://bitcointalk.org/index.php?topic=24852.0 https://bitcointalk.org/index.php?topic=24852.0]
:Seems to have gone defunct around Dec 2011. Some good ideas though and seemed to have started on execution.
* jim618 hardware wallet proposal Apr 2012 [https://bitcointalk.org/index.php?topic=77553.0 Dedicated bitcoin devices - dealing with untrusted networks]
:Great discussion and good ideas from jim618. Also linked the following video:
* Prof. Clemens Cap's hardware wallet? (video:)[https://www.youtube.com/watch?v=IavQ-Wc8S1U Clemens Cap about electronic bitcoin wallet at EuroBit]
:Clemens Cap of Uni Rostock explains the Electronic Bitcoin wallet device he's working on. It's based on adafruit microtouch device.
* ripper234's discussion based on Yubikeys Aug 2012 [https://bitcointalk.org/index.php?topic=99492 Having a YUBIKEY as one of the parties for m-of-n signatures]
:The use of Yubikeys. They only support symmetric crypto, so you'd have to trust the host device.
* kalleguld's hardware wallet proposal Oct 2012 [https://bitcointalk.org/index.php?topic=115294.0 Proposal: Hardware wallet (Win 3 BTC)]
* Vaporware: Matthew N Wright's ellet [https://bitcointalk.org/index.php?topic=85931.0 ANN The world's first handheld Bitcoin device, the Ellet!] (Vaporware)

== Smart Card based wallets ==
This type of device requires complete trust in the host device, as there is no method for user input.
See [[Smart card wallet]]

== Related Resources ==
* [http://99bitcoins.com/trezor-vs-ledger-hands-hardware-wallets-review/ TREZOR vs. Ledger] - User reviews and Reddit feedback
* slush's Hardware wallet wire protocol discussion: [https://bitcointalk.org/index.php?topic=125383.0 Hardware wallet wire protocol]
* kjj's Todo List discussion for client protocol requirements: [https://bitcointalk.org/index.php?topic=19080.msg272348#msg272348 in topic Re: Split private keys]
* paybitcoin's original post: [https://bitcointalk.org/index.php?topic=134277.0 Hardware Wallet Roundup]
* [https://bitcointalk.org/index.php?topic=135090.0 This thread] about editing this very wiki entry.
* Various Hardware Wallets and Reviews: [http://www.offlinewallets.com/hardware-wallets Offline Hardware Wallets]
* [https://www.weusecoins.com/bitcoin-ledger-wallet-review/ Ledger Wallet Review]

[[Category:Security]]
[[Category:Wallets]]
[[Category:Hardware]]

Data directory

2014-11-25T11:40:25Z

Muhammed Zakir:

The location where Bitcoin's data files are stored, including the [[Wallet|wallet]] data file.

==Default Location==
=== Windows ===

Go to Start -> Run (or press WinKey+R) and run this:

%APPDATA%\Bitcoin

Bitcoin's data folder will open. For most users, this is the following locations:

C:\Documents and Settings\YourUserName\Application data\Bitcoin (XP)

C:\Users\YourUserName\Appdata\Roaming\Bitcoin (Vista and 7)

"AppData" and "Application data" are hidden by default.

You can also store Bitcoin data files in any other drive or folder.

If you have already downloaded the data then you will have to move the data to the new folder.
If you want to store them in D:\BitcoinData then click on "Properties" of a shortcut to bitcoin-qt.exe and
add -datadir=D:\BitCoinData at the end as an example:

"C:\Program Files (x86)\Bitcoin\bitcoin-qt.exe" -datadir=d:\BitCoinData

Start Bitcoin, now you will see all the files are created in the new data directory.

=== Linux ===

By default Bitcoin will put its data here:

~/.bitcoin/

You need to do a "ls -a" to see directories that start with a dot.

If that's not it, you can do a search like this:

find / -name wallet.dat -print 2>/dev/null

=== Mac ===

By default Bitcoin will put its data here:

~/Library/Application Support/Bitcoin/

==Directory Contents==

===Files===
* .lock
**BDB lock file
* bitcoin.conf [optional]
**Contains [[Running_Bitcoin#Bitcoin.conf_Configuration_File|configuration options]].
* blk''xxxx''.dat [Versions prior to v0.8.0]
**Contains concatenated raw blocks. Stored are actual Bitcoin blocks, in network format, dumped to disk raw.
* blkindex.dat [Versions prior to v0.8.0]
**Indexing information used with blk''xxxx''.dat
* __db.''xxx''
**Used by BDB
* db.log
* debug.log
**Bitcoin's verbose log file. Automatically trimmed from time to time.
* wallet.dat
**Storage for keys, transactions, metadata, and options. Please be sure to make backups of this file. It contains the keys necessary for spending your bitcoins.
* addr.dat [Versions prior to v0.7.0]
** Storage for ip addresses to make a reconnect easier
* peers.dat [Versions v0.7.0 and later]
** Storage for peer information to make a reconnect easier. This file uses a bitcoin-specific file format, unrelated to any database system<ref>[http://bitcointalk.org/index.php?topic=119525.msg1287284#msg1287284 Ultraprune merged in mainline]</ref>.
The data, index and log files are used by Oracle [http://en.wikipedia.org/wiki/Berkeley_DB Berkeley DB], the embedded key/value data store that Bitcoin uses.

===database subdirectory===
Contains BDB journaling files

===testnet3 subdirectory===
Contains testnet versions of these files (if running with -testnet)

===blocks subdirectory===
[v0.8 and above] Contains blockchain data.

* blk*.dat
** Stored are actual Bitcoin blocks, in network format, dumped to disk raw. They are only needed for re-scanning missing transactions in a wallet, reorganizing to a different part of the chain, and serving the block data to other nodes that are synchronizing.

* blocks/index subdirectory
** [v0.8 and above] A LevelDB database that contains metadata about all known blocks, and where to find them on disk. Without this, finding a block would be very slow.

===chainstate subdirectory===
[v0.8 and above] A LevelDB database with a compact representation of all currently unspent transaction outputs and some metadata about the transactions they are from. The data here is necessary for validating new incoming blocks and transactions. It can theoretically be rebuilt from the block data (see the -reindex command line option), but this takes a rather long time. Without it, you could still theoretically do validation indeed, but it would mean a full scan through the blocks (7 GB as of may 2013) for every output being spent.

===locks subdirectory===
[v0.8 and above] Contains "undo" data.

* rev*.dat
You can see blocks as 'patches' to the chain state (they consume some unspent outputs, and produce new ones), and see the undo data as reverse patches. They are necessary for rolling back the chainstate, which is necessary in case of reorganizations.

===Personally identifiable data [v0.8 and above]===
This section may be of use to you if you wish to send a friend the blockchain, avoiding them a hefty download.

*wallet.dat
**Contains addresses and transactions linked to them. Please be sure to make backups of this file. It contains the keys necessary for spending your bitcoins. You should not transfer this file to any third party or they may be able to access your bitcoins.
*db.log
**May contain information pertaining to your wallet. It may be safely deleted.
*debug.log
**May contain IP addresses and transaction ID's. It may be safely deleted.
*database/ folder
**This should only exist when bitcoin-qt is currently running. It contains information (BDB state) relating to your wallet.
*peers.dat
**Unknown whether this contains personally identifiable data. It may be safely deleted.

Other files and folders (blocks, blocks/index, chainstate) may be safely transferred/archived as they contain information pertaining only to the public blockchain.

==See Also==

* [[Running Bitcoin]]
* [[Securing your wallet]]
* [http://bitcoin.stackexchange.com/a/11108/153 What is the database for?] Question on Bitcoin Stack Exchange

==References==
<references />

[[Category:Technical]]

[[es:Directorio de datos]]