Pages:
Author

Topic: What are ALL the ways to store bitcoin wallets? (Read 4386 times)

hero member
Activity: 756
Merit: 501
There is more to Bitcoin than bitcoins.
Hey people, I really want to understand this, but you're ahead of me.  I need this to be explained like I'm a 5 year old.

I am familiar with the wallet.dat file.  It's an object, a FILE, that I protect.  But I do not understand where, when, or how I extract a "private key".  Nor do I understand how the private key relates to blockchain.info.  

Can someone explain this stuff or give me a link?  

I've been waxing on to my friends about bitcoin, but when we get to wallet security enthusiasm wanes.

Thanks.

Private key is a random number (may be expressed as a string of random characters, of course). It is private because, presumably, only the person who created it knows it. Note, "random" can be anything (with some technical limitations), including, for example, a hash of a sentence. This is convenient if you wish to store private keys in your brain.

Public key is calculated from the priv key using the ECDSA. Note, this is a one-way function: calculating the publoc key from the private key is easy, finding out the priv key when a public key is known is practically impossible.

Bitcoin address is calculated as a one-way function of the public key. Specifically, it is a double hash of pub key, ripemd160(sha256(pubkey)).

To spend (send) coins currently associated with a given address, your client (wallet program) signs a message about the spend from the corresponding public key, and message is signed with the corresponding private key. Note, the way digital signature works is that anyone who knows the public key can check that the signature was made using the valid private key, without knowing the private key. All nodes in the network can then verify that the message is valid, and broadcast it further. Eventually, a mining node will create a new block (every 10 minutes on average), and include this message ("spend") into this block, thus making it official. Note, you can only spend the complete amount of coins associated with an address. If what you are sending is less than that, the rest goes to a new address of yours. Your total balance is still correct, of course.

What your wallet software (bitcoin-qt client, multibit, or any online wallet service) does is it creates key pairs for you, manages them, and checks balances associated with the keys/addresses you own (typically only showing you the total).

===================

Most clients will let you export ("dump") private keys. Refer to the documentation about the particular client you're using. You can then preserve private key(s) using any method discussed here. Most people print them out ("paper wallets").

You can keep the physical embodiments of your private keys hidden and secure, or you can encrypt the keys beforehand, or both. Note, bitcoin-qt client offers encryption of private keys in your wallet.dat.

legendary
Activity: 3416
Merit: 1912
The Concierge of Crypto
You can use bitcoin-qt to extract the private keys of the public keys that are displayed.

You can use pywallet (jackjack fork) to dump all the private keys of the wallet.dat file.
sr. member
Activity: 462
Merit: 250
Hey people, I really want to understand this, but you're ahead of me.  I need this to be explained like I'm a 5 year old.

I am familiar with the wallet.dat file.  It's an object, a FILE, that I protect.  But I do not understand where, when, or how I extract a "private key".  Nor do I understand how the private key relates to blockchain.info. 

Can someone explain this stuff or give me a link? 

I've been waxing on to my friends about bitcoin, but when we get to wallet security enthusiasm wanes.

Thanks.
legendary
Activity: 1264
Merit: 1008
Nice ideas but I am looking for something I can put in a tooth. 

DrG
legendary
Activity: 2086
Merit: 1035
How many places can you think to store a short string of numbers?

Convert to binary, make a binary painting for your wall.
Tattoo.
Write it in the wet cement of the foundation of your house before building it.
Piece of paper in a safe deposit box.
Hidden in a jpeg.
E-mail it to yourself through "future me".
Etch it into something you wear, ring, dog collars, necklace, etc.


Wow, somebody else thinks like me. I did that when I built my house 2 years ago.  Of course I left a few digits out of the full key, those are in another hidden area to don't tearing up my house  Tongue
newbie
Activity: 55
Merit: 0
Never knew you could store BTC on floppy dicks.

Tattoos have been mentioned already.

But hard to read when it's floppy....

Hard but not impossible which is why floppy disks particularly the older 5.25in type can be an excellent way to back up bitcoins in certain situations. The idea in is to slow down an attacker long enough in order to empty the wallet of bitcoins. Consider the following situation. One has one's BTC in a brain wallet; however one also wants to ensure that ones estate can access one's BTC after one's death but only after one's death.  One possible solution may be to place the private keys on a paper wallet in a bank safety deposit box. Then when the owner of the bitcoins dies, the executor of the estate will have after probate access to the safety deposit box and the bitcoin keys. But what happens if the bank safety deposit box is compromised, an attacker will also have immediate access to the bitcoin keys.  Now instead save the bitcoin keys in clear text on a file in a 5.25in floppy disk and place the 5.25in floppy disk in the bank safety deposit box.  In this case the attacker has to first be able to read the 5.25in floppy disk, and this gives the owner of the bitcoins plenty of time to empty the wallet. On the other hand the executor of the estate is also slowed down; however in this case it does not really matter since it can take months to probate an estate in any event.

You can you a 2 factor key.  Give one half to your family now.  the other half goes to your attorney/accountant, or whoever would handle your estate.  That way nobody has access until they join the 2 keys.

Here's how I do it:

I put one half of the key on a 5.25in floppy disk and another on a 3.5in disk. I give the 5.25in one to my family and the 3.5in one to my other family. I make sure the 3.5in one is formatted in HFS and the 5.25in in ProDOS.

legendary
Activity: 2282
Merit: 1050
Monero Core Team
Never knew you could store BTC on floppy dicks.

Tattoos have been mentioned already.

But hard to read when it's floppy....

Hard but not impossible which is why floppy disks particularly the older 5.25in type can be an excellent way to back up bitcoins in certain situations. The idea in is to slow down an attacker long enough in order to empty the wallet of bitcoins. Consider the following situation. One has one's BTC in a brain wallet; however one also wants to ensure that ones estate can access one's BTC after one's death but only after one's death.  One possible solution may be to place the private keys on a paper wallet in a bank safety deposit box. Then when the owner of the bitcoins dies, the executor of the estate will have after probate access to the safety deposit box and the bitcoin keys. But what happens if the bank safety deposit box is compromised, an attacker will also have immediate access to the bitcoin keys.  Now instead save the bitcoin keys in clear text on a file in a 5.25in floppy disk and place the 5.25in floppy disk in the bank safety deposit box.  In this case the attacker has to first be able to read the 5.25in floppy disk, and this gives the owner of the bitcoins plenty of time to empty the wallet. On the other hand the executor of the estate is also slowed down; however in this case it does not really matter since it can take months to probate an estate in any event.
legendary
Activity: 3416
Merit: 1912
The Concierge of Crypto
RAR your latest or updated wallet.dat file with 10% recovery record, and your nice long 30 character password. Install Dropbox in 20 computers, tablets, phones, ipods, etc. Sync. Email it to yourself.

For physical storage, embroider the private key on a piece of cloth, then stitch it under your shirt where it is not seen, or on the pockets or pants or other clothes you wear.

Get a money belt, they have spaces to hide real money, should be no problem to hide little pieces of laminated paper with your private keys.

Dog Tag.

Physical photo album. Hide it behind some pictures.

Handwritten in an old book. Use black oil based ink, not those water based ones. Optionally paint over it with clear nail polish.

Carve it into a wood sculpture. Or just plain carve it into anything wooden, like under you baby's crib or something.

Make some pottery statue with the private key inside, then seal it shut. They do this with drugs like in the series Lost.

Hide it in a hollowed out wax candle. Then melt the cover with more wax so it is also sealed.

Time capsule.

Engrave it on your gun (if you are into firearms). They will get your bitcoins when they pry your gun from your cold dead hands.
hero member
Activity: 707
Merit: 500
Never knew you could store BTC on floppy dicks.

Tattoos have been mentioned already.

But hard to read when it's floppy....

fuck - i had this loaded and didn't comment on it last nite. i looked at it this morning and still didn't see anyone pointing out the floppy dicks - forgot to refresh before my piss poor re-quote with a lack of commentary.
hero member
Activity: 707
Merit: 500
legendary
Activity: 1449
Merit: 1001
Never knew you could store BTC on floppy dicks.

Tattoos have been mentioned already.

But hard to read when it's floppy....
newbie
Activity: 27
Merit: 0
Morse code memorized for whistling, and passed on from one generation to the next. I know, it;s just another form of brainwallet, and a retarded one for that matter.

I think you'd have a problem with capitals letters using morse code.  It may not provide the highest security, but I bet you won't loose it if you mow it into your lawn like these people did (just make sure it's encrypted):

http://blogs-images.forbes.com/davidthier/files/2012/09/img_9933_0001.jpg
hero member
Activity: 756
Merit: 501
There is more to Bitcoin than bitcoins.
Morse code memorized for whistling, and passed on from one generation to the next. I know, it;s just another form of brainwallet, and a retarded one for that matter.
hero member
Activity: 546
Merit: 500
Never knew you could store BTC on floppy dicks.

Tattoos have been mentioned already.
hero member
Activity: 756
Merit: 501
There is more to Bitcoin than bitcoins.
hero member
Activity: 756
Merit: 501
There is more to Bitcoin than bitcoins.
legendary
Activity: 1078
Merit: 1003
Never knew you could store BTC on floppy dicks.
hero member
Activity: 899
Merit: 1002

5) Back up the encrypted cypher-text file across multiple computers, laptops tablets, smart-phones  etc. Include all computers and devices you regularly use. If malware is a concern for example a Microsoft Windows computer, do not decrypt the file on that computer or transfer the file back to a computer where the coins can be spent except as a last resort where all other backups have failed.  Also include old and vintage computers if you have them, these are an excellent for this purpose. How many current bitcoin stealing malware applications run on a 286 processor or on an old Windows 3.1 computer?

The idea is to be able to access your BTC in all sorts of scenarios ranging from a simple hard disk failure to having to flee your home, city and even country with nothing but the shirt on your back.

*** Very Important ***

Last but not least ensure that your loved ones / and or executors of your estate can access your BTC after your demise in all sorts of scenarios ranging from a simple hard disk failure to having to flee their homes, cities and even countries with nothing but their shirts on their backs.

That was helpful, thanks.  I use Truecrypt, but I don't like it--too complicated--things like 'mount' and 'dismount' are sort of alien, I wouldn't be able to teach my family that very easily.  That it's open source is good though.

Plus, I'm paranoid that I'm somehow screwing up whenever I overwrite the old wallet!

Use PySkein then http://pythonhosted.org/pyskein/ it was a NIST3 finalist and designed by Bruce Schneier and some other ppl. "pyskein threefish encrypt "   "pyskein threefish decrypt "

It produces a copy called wallet.dat.3f and leaves the original untouched if you want, or encrypts the original depending on your settings. I use it to encrypt 1 TB Virtualbox .VDI drives of software I'm working on and it flies compared to SHA256 AES.
newbie
Activity: 55
Merit: 0
Got a new one:

WORM Drive
Pages:
Jump to: