Bitcoin Forum

Here I want to discuss an overview of various methods to secure your bitcoin savings and the strengths and weaknesses of each approach for storing ones savings in Bitcoin. There is a time and place for using hot wallets, exchanges, tipping services, smartphone apps for daily spending but that is another conversation. We do not need to waste our time discussing extremely dangerous methods of storing ones savings like hot wallets and non-regulated exchanges.

Please offer any criticism and suggestions to build to this list:

Paper Wallets


Strengths:
Secure against Malware, viruses, trojans, and keyloggers. (As long as keys are generated with secure equipment) Secure against online theft initiated by hackers or unscrupulous employees and owners of online wallets. Once setup, easy to maintain and re-import. Fairly secure against State and legal theft. Practically Free to setup
Practically Free to setup


Weaknesses:
Initially difficult to securely generate with an audited and clean computer
Online Utilities not as secure as offline generators
Insecure against physical theft


Tutorials:
https://en.bitcoin.it/wiki/Paper_wallet
https://bitcointalk.org/index.php?topic=342691.0
http://www.coindesk.com/information/paper-wallet-tutorial/
https://99bitcoins.com/create-99-9-secure-bitcoin-paper-wallet/


Online Utilities to generate Paper wallets-
https://www.bitaddress.org   (Code Independently audited=?)
https://www.offlineaddress.com  (Code Independently audited=?)
https://bitcoinpaperwallet.com/bitcoinpaperwallet/generate-wallet.html   (Code Independently audited=?)

Offline Utility to generate Paper Wallets  
https://github.com/casascius/Bitcoin-Address-Utility   (Code Independently audited=?)


Devices:

1) Piper  -229 USD
http://cryptographi.com/

2) https://mycelium.com/entropy  - 40USd
released , but sold out except for reseller - http://asicminer-shop.de/Mycelium-Entropy

Concerns with paper wallets –

https://np.reddit.com/r/Bitcoin/comments/670zhy/summary_pitfalls_of_paper_wallets/

https://np.reddit.com/r/Bitcoin/comments/6ss91w/seriously_how_are_you_all_generating_your_private/dlf4uhr/


-----------------------------------------------------------------------------------------------------------------------------------
Physical Bitcoins



Strengths:
Secure against Malware, viruses, trojans, and keyloggers. (As long as keys are generated with secure equipment)
Secure against online theft initiated by hackers or unscrupulous employees and owners of online wallets.
Once setup, easy to maintain and re-import.
Fairly secure against State and legal theft.



Weaknesses:
Initially difficult to securely generate keys with an audited and clean computer
Online Utilities not as secure as offline generators
Insecure against physical theft
Much more expensive than paper wallets
Insecure unless you generate and add the private keys yourself



Sources:

1) https://www.casascius.com
In person or bulk only 500 for 0.39 BTC

2) https://www.titanbtc.com/
68 USD - ~2k USD

3) http://www.lealana.com/
various prices

4) https://www.infinitumbitcoins.com/
179 to 339 USD per coin

5) https://denarium.com/
19.9 € to 2199 € per coin



-----------------------------------------------------------------------------------------------------------------------------------

Offline Computer or device



Strengths:
Somewhat secure against Malware, viruses, trojans, and keyloggers. (As long as keys are generated with secure equipment)
Secure against online theft initiated by hackers or unscrupulous employees and owners of online wallets.
Once setup, easy to maintain and re-import.
Fairly secure against State and legal theft.



Weaknesses:
Initially difficult to securely generate keys with an audited and clean computer
Much more expensive than paper wallets(need a separate computer or device)
Vulnerabilities with possible USB /network infections if device isn't properly secure
Less reliable than physical or paper wallets, so one should backup the wallet on an additional separate key or write down a HD key phrase


Tutorials:
https://bitcointalk.org/index.php?topic=235584.0
http://codinginmysleep.com/cold-storage-part-1/
https://bitcoinarmory.com/tutorials/armory-advanced-features/offline-wallets/


Devices(besides offline computers , notepads, and laptops):


http://www.pi-wallet.com/
124.95 €

CIYAM Safe - https://susestudio.com/a/kp8B3G/ciyam-safe

12-sided dice and a TI-89 Calculator to create a bitcoin address.
http://motherboard.vice.com/read/how-to-make-a-bitcoin-address-with-a-ti-89-calculator

-----------------------------------------------------------------------------------------------------------------------------------

Hardware wallets



Strengths:
Secure against Malware, viruses, trojans, and keyloggers. (If the hardware has not been tampered with- Audits needed)
Secure against online theft initiated by hackers or unscrupulous employees and owners of online wallets.
Once setup, easy to maintain and re-import.
Fairly secure against State and legal theft.
Easier to actively make secure transactions, without needing to import private keys


Weaknesses:
Few of these devices has been thoroughly independently audited
More expensive than paper wallets
Less reliable than physical or paper wallets, so one should backup the wallet on an additional separate key or write down a HD key phrase

Comparison of
KeepKey vs Trezor vs Ledger Nano
https://www.youtube.com/watch?v=aOnOBl_MxmQ


Devices:


1) Trezor
https://www.bitcointrezor.com/
Original 99 USD
TREZOR model T - preorder 139 € - 149 €
Source Code: Open source

https://www.youtube.com/watch?v=pT1j_kbZBEo

2) ledger wallet
 https://www.ledgerwallet.com/
Ledger nano S  58.00 €
nano 49 usd (will not have future firmware upgrade support soon)
HW.1 23 usd (will not have future firmware upgrade support soon)
Ledger Blue - 229 €
Source Code: open

https://www.youtube.com/watch?v=YI1OntWB7wc

3) Keep Key
https://www.keepkey.com/
129 usd
Source Code: Open source

https://www.youtube.com/watch?v=bs4N3jtZrEI

4) Digital Bitbox
https://digitalbitbox.com/
54 €
Source Code: open

https://www.youtube.com/watch?v=VBfgG-WXzhc

5) Open Dime
http://www.opendime.com/
29 usd for 3
Unique HW wallet that acts as a fungible and verifiable offline form of currency

https://www.youtube.com/watch?v=1LrKLsZYGjQ

https://www.youtube.com/watch?v=QqkKtJSPvlU

-----------------------------------------------------------------------------------------------------------------------------------

Muti-sig Hot wallets and services



Strengths:
Somewhat secure against Malware, viruses, trojans, and keyloggers. (As long as keys are generated with secure equipment)
Somewhat Secure against online theft initiated by hackers or unscrupulous employees and owners of online wallets.
Easy to setup and maintain
Easier to actively make secure transactions, without needing to import private keys
Added features such as 2FA , online access, and Insurance


Weaknesses:
None of these services have been thoroughly independently audited
Concerns that private keys generated with the service are also stored or captured by companies
Vulnerable to malware,  trojans, and keyloggers within the browser (mainly at time of creation)
Vulnerable to privacy concerns
Vulnerable to legal and state theft

Tutorials -
http://sx.dyne.org/multisig.html
https://www.youtube.com/watch?v=zIbUSaZBJgU
https://www.youtube.com/watch?v=ZKRLJGBMqWo



Services:


1) https://greenaddress.it
 2-of-2 or 2 of 3 multisignature with nLockTime (possible temporarily unable to spend funds) / Free
https://bitcointalk.org/index.php?topic=521988.0

2)https://www.bitgo.com/
2 of 3 multisig / Free
 
3) https://www.coinbase.com/vault
2 of 3 multisig / insured / Free

4) https://www.bitalo.com/why_bitalo
 2-of-2 multisignature


-----------------------------------------------------------------------------------------------------------------------------------

Muti-sig Paper/electronic wallets


Strengths:
Secure against Malware, viruses, trojans, and keyloggers. (As long as keys are generated with secure equipment)
Secure against online theft initiated by hackers or unscrupulous employees and owners of online wallets.
Once setup, easy to maintain and re-import.
Fairly secure against State and legal theft.
Practically Free to setup
Secure against physical theft if only one of the private keys is physical and the other 2 are encrypted and stored independently.


Weaknesses:
Initially difficult to securely generate with an audited and clean computer (with exception to entropy)
Online Utilities not as secure as offline generators



Tutorials:


1) Armory
https://www.armoryguide.com/OfflineWalletSetup.html
https://bitcoinarmory.com/tutorials/armory-advanced-features/offline-wallets/
https://bitcoinarmory.com/tutorials/armory-advanced-features/lockbox/create-lockbox/
https://bitcoinarmory.com/tutorials/armory-advanced-features/fragmented-backups/


Devices:


1) https://mycelium.com/entropy  - 40USd
released , but sold out except for reseller - http://asicminer-shop.de/Mycelium-Entropy


-----------------------------------------------------------------------------------------------------------------------------------

Brain wallets


Strengths:
Secure against Malware, viruses, trojans, and keyloggers. (As long as keys are generated with secure equipment)
Secure against online theft initiated by hackers or unscrupulous employees and owners of online wallets.
Fairly secure against State and legal theft.
Free to setup
Secure against physical theft but not torture


Weaknesses:
Difficult to remember
risk of forgetting private keys
Difficult to re-import
Risk the passphrase isn't secure


Tutorials:


http://www.coindesk.com/how-to-create-a-brain-wallet/
https://bitcointalk.org/index.php?topic=710434.0


Tools:


1) https://brainwallet.github.io/

-----------------------------------------------------------------------------------------------------------------------------------

Manually Creating a Wallet


Strengths:
Secure against Malware, viruses, trojans, and keyloggers.
Secure against online theft initiated by hackers or unscrupulous employees and owners of online wallets.
Fairly secure against State and legal theft.
Sometimes free to setup


Weaknesses:
Time consuming
Difficult to securely generate
Insecure against physical theft once written down


Tutorials:


https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses

How is it that physical bitcoin difficult for the government to seize? Would they not be able to seize them the same way they would seize a TV (for example) that is in your house?

^^This is not true for any of your security methods. In order for this to be true you must create the private key on a computer that is not infected with any of the above. If you attempt to create a private key with a computer infected with malware then your private key will not be private

Thanks for your input. :)


Paperwallets and physical bitcoins are difficult for governments to seize because they have to physically find these small items that can be hidden. With Multisig added as another layer to paper wallets, it makes it much more difficult as a thief(state or individual) to uncover or even be aware of a set of the keys that can be stored in different locations and or different methods.

So say you purchased or received some bitcoins, as soon as they are transferred to a new address(in this case paper wallet /physical BTC) that isn't link to your identity there is no trace if you lost it, sold them , gifted them, ect..

What would be ideal is generating your own random seed and using a device like entropy to generate a 2 of 3 multisig, where one of the 3 keys is placed in a encrypted password manager(physical key destroyed after) , the second key is laminated and stored in a safe or hidden location, the last key is stored physically in a third location that is not routinely checked.


This is the reason I listed "Initially difficult to securely generate with an audited and clean computer" as a weakness , but I will reinforce the principle in the strengths as well now.

I think bicointrezor is the best device for BTC wallet security. With time, can be some problems with electronical parts in this device - I think after ~ 10 years, but you can change device after let say 8 years.

Don't become a victim-
https://bitcointalk.org/index.php?topic=875805.0

Immediately store most of your wealth using one of these methods.

I would vote for Trezor Hardware wallet for the moment , I think it's the best even if the price is a little bit high i guess it worth it.

also Mycelium Bitcoincard https://mycelium.com/bitcoincard looks interessting , cant wait to see it when they finish developping it

I would vote for whatever you are most comfortable with. I already have a proven system to secure and manage private keys used to encrypt/decrypt sensitive and important information related to my line of work. I simply extended it to protect my wallet.dat - I PGP encrypt my wallet and store redundant copies in plain sight in the cloud.

hopefully we see some more good and cheap hardware wallets. i would use one maybe  :)

I think at least two levels of security in both physical and software are needed: Either a bip38 encrypted paper wallet, or a password protected usb drive

Unlike using a traditional bank, you need to keep some backup of your wallet, it is this part most troublesome, since the backup should have the same or higher security level than the main storage, otherwise it will become the weakest point of the system

I'm personally a fan of using a brain wallet.  One advantage I haven't seen
listed is the portability factor -- if you're in travelling broad, you
can still access your coins.  If you have to leave your home
or your country, you can access your coins.  Your coins are safe
from fires, floods, earthquakes, etc.

The risk of forgetting a password/passphrase is a factor, but
it is also a factor in other kinds of wallets.  And you can make
an encrypted backup of your passphrase somewhere.

 

I might get the chance to test a prototype of the Mycelium Bitcoincard. I am pretty excited about that ;)

you should remove

4) https://www.bitalo.com/why_bitalo
 2-of-2 multisignature


because their website is offline since weeks  :-[

Thank you so much for this.

I will try setting up a brain and paper wallet later this week.

Key vulnerability of hardware wallets or offline computers is they can break down, without need to be physically damaged (unlike a paper wallet)

electrum would be the best for this ...

Thanks, done...  They may come back but the fact that they have been down this long makes me not even want to mention them regardless.


Agreed, updated.

Added Cryptolabs "case" harware wallet to list of things to look forward to.

http://www.choosecase.com/

http://techcrunch.com/2014/11/17/cryptolabs-launches-with-bitcoin-storage-hardware/

The CIYAM Safe (https://susestudio.com/a/kp8B3G/ciyam-safe) is another offline transaction signing solution (100% air-gapped by usage of QR codes and cams).

Which one is best ?

Thanks, I added that to the Offline Computer or device section. Great alternative.


There is no best. All have advantages and disadvantages. I personally like the option of combining Muti-sig Paper wallets where one of the partial-key is stored digitally and password protected.

usb cold storage connected for backup the wallet,  to a secure pc(secure erased first, first thing you do is connecting the usb) is the most secure/fast/anti-lazy thing to secure your bitcoin ihmo

i'm doing this, and never had any problem, i also use a wallet trap with a small amount, this let me know if my pc is secure

Same here.

I have a wallet without encryption with around 0.2XBT in it just to see if my pc is safe.

I know that doesn't mean your pc doesn't contain virus or mallware, but it helps.

Added -

https://www.ledgerwallet.com/
29.00 €

http://www.coindesk.com/ledger-launches-usb-bitcoin-wallet-bank-grade-security/

readded - 4) https://www.bitalo.com/why_bitalo
 2-of-2 multisignature

Voting for Offline wallets like Electrum . and in case a computer failure , you can just get your wallet back without any issues.
Brain wallets are very secure too but really hard to remember with time...

Electrum can be very secure but a simple plastic paper wallet in a safe works fine.

Update on Trezor-

No longer open source LGPLv3 as of  v1.3.0 and switched to restrictive Microsoft Reference Source License

https://github.com/trezor/trezor-mcu/commit/2147c5fc88a28151d66afa46df0d918e598c0428


Updated all prices and removed
https://www.cryptmint.com temporarily till more info comes in. 

This is some great information. Thank you for keeping it updated.

i prefer paper wallet, as only thing to worry about is physical theft, but for physical theft you can't blame bitcoin of other as gold and fiat currency are also not secure against physical theft

One thing to be very careful about is how you generate your paper wallet as @gmaxwell has recently pointed out you would not be wise to use any current .js wallet generator (such as bitaddress.org and even if offline) due to potentially poor random number generation and code that has not been thoroughly peer reviewed.

Secure Paper Wallets (https://bitcointalk.org/index.php?topic=833283.msg9310260#msg9310260)

Paper wallets are the most secure.
They are vulnerable to physical theft,
read my post to have the most secure cold storage possible.

New Hardware wallet added-

6) BWallet
https://bidingxing.com/   http://www.coincola.com/products
28.00 USD

Appears to be a Trezor Chinese knockoff

very good your post. I enjoyed the reading I've done. Congratulations.

Well I use paper wallet but nowadays I develop that sense of insecurity of having the paper getting stolen and the private key revealed. And also since it is just a paper, there's a chance for the ink to fade off someday. Been looking into hardware wallet so more or less I have narrowed down to few options such as trezor or btchip.

Are there any better ways of generating paperwallets? (ideally not too complicated)

Kind of assumed that offline bitaddress was very secure.

Without any proper peer review I'm not sure why you assumed it is secure (just because others use it?).

The latest version of Bitcoin does display a QR code when you create a new receive address so although not perfectly simple it shouldn't be too hard to print that from an offline computer that is running it (it is simpler when using a console when you have tools such as "qrencode" but I understand that isn't easy for most).

I recently bought a laminator for that purpose. Haven't used it, yet ^^

Combining physical security and digital security is good option. Use acid free or Archival paper that is laminated with multisig. One concern is that with hardware wallets you ultimately still have to back it up and typically with 12 word mnemonic from a HD wallet which essentially makes it only as secure as a non-multisig paper wallet. You can split the words up between multiple locations but than if one of the shards of your 12 word mnemonic gets lost or stolen than you lose the ability to recover your wallet unlike with a m of n multisig which allows you to lose some of the keys.

I personally like multisig wallets where 1 key is encrypted in a password manager, one key is laminated in a safe, and one key is in a off site time capsule. This ensures that I am both protected from viruses and trojans, thieves breaking into my house, accidents or forgetfulness, and still can move the funds fairly quickly to my cell phone if I am in a hurry. For this reason it may also be wise to split your savings between multiple paper wallets so you don't have to restore all of your savings from a paper wallet either and a smaller portion if you need some quick cash.

 
Currently, the best way to generate secure paperwallets is to perform a fresh install of a linux distro combined with armory on a spare computer.

The easiest and most secure way to generate multisig paperwallets will be the Mycelium Entropy once it is released. When I get mine I will audit and review it for everyone.

ok thanks for the info, think I'll try out Armory on Linux and see how I get on.

I consider brainwallets to be one of the easiest and safest option - except you store it as a paper wallet, not actually remembering it by head.

A random mnemonic word list as brain wallet input, e.g. private key = SHA256("fiction bronze tent grant stock sister across hotel document mad afford faith assume dust") which you can simply write down on a piece of paper is very safe, imho.

Of course, granted you're entering these words (and generating the SHA256 hash, and base58-encoding it to a Bitcoin private key, and extracting the corresponding address) on an offline computer. A local copy of bitaddress.org would suffice.

Good thread. You say "Insecure against physical theft" for the paper wallet, but you can secure it pretty well against physical threat if you encrypt it and store it safely in a bank safe or two on a form that resists to moisture or heat.

Read the - "Muti-sig Paper/electronic wallets" section and the other posts in this thread.


This would be secure as a paper wallet but if done manually would remove the risk of an unaudited paper wallet generator being compromised. The entropy device has open source code that once completed will be audited and allows you to enter in your own seed - https://github.com/mycelium-com/entropy

In a couple weeks when these start to ship many people will start testing and auditing the code. After enough scrutiny you should be very comfortable using this device.

Does anyone have a database of how many security researchers have audited other hardware wallets and devices?

I've been studying Multi-sig as a means of securing the bulk of my BTC, but I have a question about it. I've seen several guides on setting up multi-sig, such as using the tool at bitaddress.org which provides a public key and multiple shared keys, which I presume are the private keys needed to access the funds.

BUT, nowhere have I been able to find an explanation of how to actually spend funds sent to a multi-sig public key. Do I import the keys into a wallet like Electrum and then generate Spends of identical amounts using each private key and to the same recipient address? Seems simple enough (if that's accurate) but this detail keeps getting skipped in the setup guides. What if the recipient address is the same but the amounts are different, etc?

My thought right now is that I'd like to use Electrum (etc.) with a bitaddress.org-generated multi-sig set of keys, then distribute the keys onto multiple computers that I have, so that a hacker would need to somehow gain control of a couple at one time, which is vanishingly unlikely. But before I send any BTC in, I want to be certain I know how to get the funds _out_.

Seeing how long everyone have wrote here , i would just say what i prefer
Offline wallet and Brain wallets
Easy and safe

This depends upon the method you have used to create the multisig.

For armory it is called "fragmented backups"

https://bitcoinarmory.com/tutorials/armory-advanced-features/fragmented-backups/

For Mycelium entropy you scan the required keys in-
https://www.youtube.com/watch?v=2NxrHSKOBjI

More detailed explanation of how to spend multisig with a more manual process using python -
https://www.youtube.com/watch?v=OSA1pwlaypc&index=13


Essentially, it works like restoring a HD backup for most devices but you import multiple keys. This is why I recommended that you have multiple multisig backup wallets as you may only need to take a small portion of your savings in cold storage out and import them to a hot wallet to spend. You could label the paper wallets to tell them apart but most will also reflect the public key along with the private so you don't mix them up.


Be careful with brain wallets as creating enough entropy without using common phrases found in literature and lyrics can be difficult to accomplish and than you need to have sufficient memory to remember the phrase. Additionally, with no physical security you could be tortured (water boarded) to provide the evidence, there is no way to tell that some of the keys have been compromised until it is too late, or you just forget the key overtime. Brain wallets have their purpose and usefulness but definitely not something I would recommend for most. The fact that you rarely use the brainwallet pass phrase and it needs a lot of entropy makes even individuals with good memories likely to forget them.
 

In any case, I would really prefer a paper wallet laminated and kept in a safe place. No hassles at all, and when the time comes that I need to get the balance in there, I would just sweep it out and tada!

Thanks; if anyone has a non-video guide, though, I'd appreciate it, especially as it relates to bitaddress.org-generated keys. My corporate firewall blocks youtube and home internet is limited to 4 GB/month so I can't spare the bandwidth.

https://www.reddit.com/r/Bitcoin/comments/2t5yzb/stepbystep_guide_store_your_bitcoins_in_a/
https://www.armoryguide.com

OK, that Reddit guide was exactly what I needed. Or just a slight bit more explanation on the Split Address tab of the bitaddress.org page would have been sufficient too. Thanks!!!  I'll be able to proceed with my testing now.

Again I point to my old thread.
Encrypted paper wallets, step by step. (https://bitcointalk.org/index.php?topic=833283.msg9310260#msg9310260)

I've put the steps to securing your private key in an accessible and portable format.
This whole discussion has gone on too long.
Hardware wallets can be good, they also may have security holes that may never get fixed.
Multisig paper wallet is more secure than a regular paper wallet, it is not necessarily a more secure method than a single encrypted paper wallet, and seems not accessible or portable enough for many end users.
Encrypted paper wallets are the most secure option. They are as secure as the method you use to encrypt your private key, and you can get batshit crazy and encrypt it with many super complex well proven encryption methods.
Humans are the weakest link on the strongest methods of storing BTC.

i have backups stored on several drives and also made paper wallets.
i think my security is decent enough.

Redundancy != security.

A paper wallet is no more secure than the safe you put it in.
Storing your wallets on several drives just makes your wallets less secure.

If you can connect the words it is quite easy, though it's upto you , but am good with memory but still to make it easy i made it into a rhyme and then another rhyme which reminds me of it and i coded it upon that and i sing that to my daughter every weekend night , thus wont forget it :)
Thanks for the heads up though
~appreciated :)

It's the problem of Risk of Loss versus Risk of Theft that I raised in my Security Paradox thread (https://bitcointalk.org/index.php?topic=962306.0). If you don't make multiple copies you stand a very high chance over time of losing your only copy. I think the M of N solution raised on that thread is the ideal compromise. (Similar to multisig, it requires you have M of N keys/passwords to access your funds, where M is a number larger than 1 but several steps lower than N so you can tolerate losing access to several passwords/keys.)

Could you review the bitadress.org-code? I think, that is what most people use, nowadays.

https://www.youtube.com/watch?v=NKqHXoYZvMg

How to Store and Use Bitcoins

Good post on hardware wallets - https://bitcointalk.org/index.php?topic=899253.0 

I updated the hardware wallet section.

http://motherboard.vice.com/read/how-to-make-a-bitcoin-address-with-a-ti-89-calculator

12-sided dice and a TI-89 Calculator to create a bitcoin address.

https://www.reddit.com/r/Bitcoin/comments/3107me/demo_bitcoin_diceware_on_a_ti89_graphing/cpxj4v9

Pros;

    The RNG is improbable to be weak.
    The RNG is impossible to be backdoored.
    Privkey never enters a networked system.
    Privkey cannot linger in memory or hardisk (there's none).
Cons;

    Very obscure.

I used poloniex exchange and enable GA(very important), it's safe and reliable, I have used there over 1 year.(maybe longer I am not sure)

Although poloniex was hacked long time ago, they didn't run away with customers' funds, it's the best altcoin exchange.

This is poor advice and likely a mistaken post. Exchanges are merely tools to temporarily use to exchange between coins or currencies and never a secure option to safeguard your savings.

Even well regulated insured exchanges are insecure against multiple forms of theft such as "legal" theft under litigation and asset forfeiture, fraud and terrorism suspicions freezing your funds, and tax theft to name a few.  

Paper wallets seem to work well for me for now. Interested in possibly getting a hardware wallet down the line but will have to see.

The idea of using the TI89 was interesting, hadn't seen that one. The comments on reddit mentioned some possible security concerns with it, but it also seems like it'd be an annoying process lol.

I won't go into the exact details, but I have a couple of BIP38 encrypted paper wallets - so if they're lost or stolen it isn't a big deal (as long as you're password is of sufficient complexity). Because I don't actively have any need to move large amounts of coins I don't run a cold storage system with offline signing, but my advice would be an offline version of Armory making use of a Linux distro (confirm SHA and MD5 sums) which you can use to sign transactions. As usual keep everything encrypted in the case of physical theft.

Good advice but has the downfall of human error with some people with bad memories who forget the passphrase to unencrypt their private keys.

The other way is to use either Shamir’s 2-of-3 Secret Sharing Scheme or mutisig to secure your backup of cold storage where all you have to do is remember the physical location of the keys.

Entropy uses Shamir’s 2-of-3 Secret Sharing Scheme
http://asicminer-shop.de/Mycelium-Entropy

One Question:

What do you recommend?

There isn't one recommendation as people should use multiple wallets and be willing to weigh risk/convenience.

What I do now -
Spending - Use Mycelium HD wallet(with pin) on my android with 200 usd of bitcoin max. HD seed backed up physically in safe.
Spending - Use Bitcoin QT wallet on my primary computer with 200 usd of bitcoin max with a completely unique and high entropy password. There are many security practices that need to be done with primary computer.
Savings - Entropy with Shamir’s 2-of-3 Secret Sharing Scheme for my cold storage savings where 1 key is encrypted in my password manager, the second key is laminated in my safe, and the third key is laminated and secured in an offsite location.


What is slightly less secure but acceptable for many-
Spending - Use Mycelium HD wallet(with pin) on my android with 200 usd of bitcoin max. HD seed backed up physically in safe.
Spending - Use Bitcoin QT wallet on my primary computer with 200 usd of bitcoin max with a completely unique and high entropy password. There are many security practices that need to be done with primary computer.
Savings - offline computer with clean fresh linux install that never touches any external HD / memory/ network that the primary computers touch and with no extra software installed and just used to store your bitcoins. It is better to physically disable your network wifi card but acceptable to simply not connect to the network unless needing to download the blockchain.

Or using a hardware wallet, or using multiple paper wallets/coins with different ballances on them and properly secured(if they are created securely.

In other words you need to read the information in the first post and use cold storage for security of your savings.

Hey I'm using windows 8.1 RT and I cant download anything from outside except the store and the Store Doesn't have any Bitcoin related Applications! Now how do I setup a cold wallet? :(

All the information is listed in the first post. I would suggest you get a laptop that doesn't run windows RT either(No one should subject themselves to RT). In the meantime you will need to use a different computer or get a mycelium entropy. If you are really paranoid you may have to temporarily store your bitcoins in a multisig hot wallet service(4 examples referenced) until you can get the right resources to secure the bitcoins yourself.

I have to say none of this scheme are simple enough, at the same time, secure enough.
We need something more simple and easy to use.

You can't. Windows 8.1 RT can best be described as a Portable Orwellian Telescreen. Only those applications authorized by Big Brother (Microsoft and the MPAA) are permitted and Bitcoin is not one of them. I would recommend a computer running GNU/Linux for anything related to Bitcoin.

Really? I used it for over 2 years, and never been hacked, I have stored there over 100btc, Google authenticator is secure enough, to make wallet secure, GA is neccessary.  ;D

I know some cases who lost a few bitcoin(0.X btc) in local wallet, it's not secure at all. Trojans may destroy local wallets and steal bitcoin.

And we are also all very well aware of the thousands of users who lost everything with hot wallets and exchanges that get "hacked".
Your advice is very odd considering what has happened over the last 3 years where more was stolen with exchanges and hot wallets than any other way. poloniex has multiple red flags as well and thus even more suspected than exchanges like coinbase.

Do you work for, work with , or have some special financial relationship with poloniex ?

This is one long but very useful post.
I have a lot of reading and safety measures to take.

So far I have my wallet stored on off-line (never used) equipment and on usb.

Is that not safe enough?

Odd of both usb broken and equipment failed at the same time is small but non-zero.

So what do you suggest?
Paper wallets?
Multisig paper wallets maybe? (for extra security)

What would be a fail-proof solution in your guys opinion?

You are somewhat secure.

As long as all the devices are secure and you backup your HD seed or another wallet backup in another usb stick and store that in a secure location offsite and encrypted with a high entropy unique password than the only risk you may have is the original machine being compromised (unlikely as long as you took a few precautions) or you forget your passphrase.

This is where using either mutisig or Shamir’s 2-of-3 Secret Sharing Scheme comes into play because it protects you from both physical theft, hardware failures, or you developing amnesia and forgetting the passphrase.

It is also a good idea to split up your balances so not all of it is saved in one device in case it gets exploited and all your private keys stolen in one transaction. With paperwallets this is easier done.

There is no such thing as a fail proof solution. If you're not dealing with some great amounts of bitcoins, i would just recommend paper wallets.
There's no point in having bank-alike security/safety for amounts of a couple of thousands USD at best. You're overthinking it.

cheers

I like brain wallet the best just make sure you never fall into a coma or start to forget things. maybe writing it down on a paper and placing that under a magnet on the fridge is a good idea too,.

Got it. Thanks.

One more question: Isn't multisig the same as Shamir’s 2-of-3 Secret Sharing Scheme? (this is the first time I have heard of this by the way)

No they are completely different.

Bitcoin supports two multi-signature schemes:
M-of-N Standard Transactions
https://github.com/bitcoin/bips/blob/master/bip-0011.mediawiki

Pay to Script Hash
https://github.com/bitcoin/bips/blob/master/bip-0016.mediawiki
---------------------------------------------------------

SSSS - Shamir's Secret Sharing Scheme found here:

https://github.com/cetuscetus/btctool/blob/bip/bip-xxxx.mediawiki

Paper wallet still the safest if you know how to keep it safe.

The idea of needing several pieces of paper (which you will have spread across the homes of different trusted persons like parents/brothers) is pretty stressing... you never know what would happen, you could still get in a fight with the so called trusted third parties and they could unintentionally lose the papers anyway.

Valid concern. With SSSS or multisig they have no power to steal the funds and only make your backup slightly more insecure if you also make a mistake and lose your backup as well. You could always store one of the shards in a security deposit box or test tube in offsite location if you can't trust anyone as well.

http://www.coindesk.com/case-bitcoin-wallet-pre-order/

Only 1,000 Case wallets will be available for  pre-order for $199 or roughly 0.83 BTC .

What are the benefits of this wallet over the other ones?

Combines multisig where Case holds one of the keys as a backup for you but cannot steal your funds and includes fingerprint biometrics and uses its own GSM signal to communicate with the blockchain so you can make payments without internet.

http://www.choosecase.com/faq.html

Case connects to 183 mobile carriers in 109 countries: Afghanistan, Albania, Algeria, Anguilla, Antigua and Barbuda, Argentina, Armenia, Aruba, Australia, Austria, Azerbaijan, Bangladesh, Barbados, Belgium, Bermuda, Brazil, British Virgin Islands, Bulgaria, Canada, Cayman Islands, Chad, Chile, China, Colombia, Cote de Ivoire, Croatia, Cyprus, Czech Republic, Denmark, Dominica, Dominican Republic, DR Congo, Ecuador, Egypt, El Salvador, Estonia, Faeroe Islands, Finland, France, Germany, Ghana, Greece, Grenada, Guatemala, Guyana, Haiti, Honduras, Hong Kong, Hungary, Iceland, India, Indonesia, Ireland, Israel, Italy, Jamaica, Japan, Kazakstan, Laos, Latvia, Liechtenstein, Lithuania, Luxembourg, Malaysia, Malta, Martinique, Mexico, Montserrat, Namibia, Netherlands, Netherlands Antilles, New Zealand, Nicaragua, Nigeria, Norway, Pakistan, Panama, Peru, Poland, Portugal, Republic of Korea, Romania, Russian Federation, Rwanda, Saint Kitts and Nevis, Saudi Arabia, Singapore, Slovakia, Slovenia, South Africa, Spain, St. Lucia, St. Vincent and the Grenadines, Suriname, Sweden, Switzerland, Tanzania, Thailand, Trinidad and Tobago, Turkey, Turks and Caicos Islands, Uganda, Ukraine, United Arab Emirates, United Kingdom, United States, Uruguay, Uzbekistan, Venezuela.

Warning - Do not use this hardware for money laundering or illegal activities as they are a US company that does store some data on their users. It is likely they will comply with investigators.


Biometrics are convenient which creates a security benefit because you will use a sufficient amount of entropy on your password... but also have severe disadvantages because you end up leaving all your passwords everywhere in public and cannot change it if it gets compromised.

Still looks like a neat device, but thanks for the warning. My larger concern is the security of it using biometrics... I tend to leave my fingerprints everywhere!

https://www.youtube.com/watch?v=Zw6kWtehqEQ

What is Case Wallet? An interview with Melanie Shapiro

For securing my wallet,
personally I will choose a paper wallet,

because paper wallet cannot be hacked or cracked,

its depends to ourselves to secure it,

but, if the paper lost,
you lost all of it...  :(

well yeah its a good thing if you have no bad friends who can just take it if they find it by accident

http://www.eliptibox.com

added to hardware wallets

Not entirely true, especially if you don't know what you're doing and create it on a compromised computer or website. You can also lose or damage or it gets accidentally destroyed. And this is why I prefer the following option. Create a wallet with a client that can be restored from a seed that you write down. Then write your private keys down safely. Then back-up your wallets safely on external mediums like usb drives or a cd-r. This way you're three times protected. Lose your wallet or it becomes corrupted? Then you've got the private keys written down. Lose the private keys? Then you can restore from seed. Don't ever just rely on one back-up or way of backing up because so many things can go wrong.

updated the HW1 info

Paper Wallet or physical coins.

i choice Offline computer or device..is more save for wallet

Surprising result, I would have thought hardware wallets would be one top of the list, it my preference. I love how some wallets are now integrating Trezor, and I'm able to connect it to my phone, it was the only downside for me using the Trezor, no phone support.

Iam going with offline computer or device
An offline wallet, as we known as cold storage, provides the highest level of security for savings.
And of course It involves storing a wallet in a secured place that is not connected to the network.
And when you do that properly, it can offer a very good protection against computer vulnerabilities.
For me using an offline wallet in conjunction with backups and encryption is also a good step and choice :)

I think next month I'll use cold storage because is saver than the other
But I'm confused to choose between offline wallet or paper wallet  ???

Well I have so many raspberries with LCD screens laying around, would be fun to make some offline wallets. Got some awesome casings that are not used atm.

Posted From bitcointalk.org Android App

https://www.youtube.com/watch?v=Dedk_840tts

What's up next for hardware wallets?
Thomas France & Eric Larcheveque, Ledger Wallet

--------------------------------------------------------

https://www.youtube.com/watch?v=Wnxi5QksVoo

Keep Key Review - Bitcoin Hardware Wallet

Use of brain wallets discouraged because of anthropic limitations in creating sufficient entropy. https://brainwallet.org permanently shutdown to discourage its use. http://insecurety.net/?p=866
https://rya.nc/cracking_cryptocurrency_brainwallets.pdf
https://github.com/ryancdotorg/brainflayer

you could also use 2FA for securing you're wallet (however, that could not be as secure as the other types...)

A mixture of a few options with your bitcoins spread out would be best, that is what im working on.  Next up im going to get me a trezor and try that out. Since they just reduced it in price im expecting version 2 to come out.

Most of the vulnerability of brainwallet came from using a single round of a simple hash (SHA256) and lack of (suggested) salt, which made brute-force & dictionary attacks very cheap.

Using a more complex hash and some basic, easy to remember, globally unique salt, the vulnerability is greatly reduced. WarpWallet does something like that, and attacks like brainflayer are greatly mitigated, since they not only need to perform more complex hashes (at a much lower rate than vs a single SHA256 round), but the attack also has to be targeted to the salt (like a globally unique email address), and the hashing cannot be reused for other salts.

Just the complex hash already makes it hard, the 8 alphanumeric warpwallet challenge still has not been solved, with a single SHA256 round, it would probably have been solved within a day.

(that said, using billions of rounds of sha256 should work just as fine as using scrypt, and could be more future-proof, since SHA256 asic performance has plateau'ed, while scrypt-asic have huge future improvement potentials, it's always possible there will be SHA256 breakthrough, but IMHO Scrypt breakthroughs are more likely)

It's very nice to know that Shamir's Secret Sharing Scheme is getting more popular as a tool for cold storage.

There's an implementation called PassGuardian that helps a lot with that task.

I've added info about it under my list here: https://bitcointalk.org/index.php?topic=1164163.0 (https://bitcointalk.org/index.php?topic=1164163.0)

Very nice nice and rich sources of highly needed information for both beginners as well as the advanced bitcoin users. (Professionals themselves have these ideas). While making some bitcoins through faucets, I keep on thinking on how to secure my hardly earned bitcoins. I find the feasible answer here. Thanks for such a helpful threat.

hardware wallet is the best option :D

I think so... but I don't have a 2TB hard drive...

Not really. If you use Trezor the 24 word seed generates all your addresses and private keys. You can consider the seed your wallet, not the plastic device. If you lose your Trezor all you need is to recover from seed using a new Trezor. Or you can use another BIP32, BIP39 and BIP44 wallet like Electrum.

Write your seed on paper and you can consider Trezor a "paper wallet" you can actually use daily. No one has been able to argue that Trezor is not secure. Some nitpick that there is some lack of privacy because you can not yet use Trezor with a full node like Bitcoin Core, but Armory has stated that a new release will support Trezor, erasing that last objection.

Anyone with more than a few bitcoin who is not using cold storage is taking a rather large chance. Trezor is the most convenient way to use cold storage and a bargain at $99. Ledger is another choice at $40 but it is worth spending an extra $60 to get the screen on Trezor.

Updates -

9) BitLox
http://www.bitlox.com/
BitLox Advanced  199 USD
BitLox Ultimate    299 USD
BitLox Extreme Privacy Set   399 USD
Source Code: Open source apps

8 ) Digital Bitbox
https://digitalbitbox.com/
120 usd
Source Code: open

10) eWallet
http://www.blackarrowsoftware.com/store/ewallet.html
39 usd
Source Code: open

11) Goochain Citadelle
https://goochain.net/citadelle/
14.50 €
Source Code: ?

12) Open Dime
http://www.opendime.com/
29 usd for 3 on backorder
Unique HW wallet that acts as a fungible and verifiable offline form of currency


Removed eliptibox, hardbit, and edited many other HW wallets

5) https://www.infinitumbitcoins.com/
99 to 399 USD per coin

6) https://denarium.com/
13,70 € to 469,42 € per coin

I most likey to use wallets that can use 2FactorbLogin so even if your wallet is been hacked you can still recover it and the hacker cannot log on your account and steal your money.But it is still better using physical coins or paper wallet because it is more secured for me.Thats my opinion anyone have  choice from what wallet they will use.

Added new coin

BTCC mint preloaded Titanium Bitcoins (not sold in US)
https://mint.btcc.com/  
1.1BTC per coin (Includes virgin 1 BTC)

Added Ledger Blue Announcement

Added -

Ledger nano S  58.00 €

for me,securing bitcoin only have to choice,store it on online wallet with full security method,or secure it hardware wallet and keep carefull with usb wallet. i think it normal,hardware orpapper wallet almost have same function,even papper wallet more easy to use and purcase. and for now i rather to use online wallet with good security.

Ledger is taking pre-orders for the new Ledger Nano S to ship in July. This will be the first hardware wallet for both bitcoin and ether and buying one is a no brainer at $66. You will be able to store private keys for the top two cryptos in one hardware wallet. Brilliant!

https://bitcoinnewsmagazine.com/wp-content/uploads/2015/08/ledgernanos.png

This seems to be the newest product from ledger, i currently hold the Ledger Nano but this seems to be different and maybe like trezor or keepkey? by controlling the transaction outside computer with those two buttons?

KeepKey is a Trezor clone made by an outfit who took the Trezor open source code to build a business off the back of original hard work done by the Trezor developers. Ledger is a true competitor who took a different approach using a secure element. From the information Ledger has released the Nano S works similar to Trezor and there are two buttons on the side you can see in the photo posted.

Instead of plugging into a USB port like current Nano the Nano S has a micro USB female port same as Trezor and ships with the required cable. You will also be able to use it with Mycelium on your phone like Trezor.

Main differences from the Trezor other than the secure element are the PIN is limited to four numbers and passphrases are not enabled. @btchip has already mentioned that the company is amenable to correcting both in a firmware update.

updated many items including this -

Concerns with paper wallets –

https://np.reddit.com/r/Bitcoin/comments/670zhy/summary_pitfalls_of_paper_wallets/

https://np.reddit.com/r/Bitcoin/comments/6ss91w/seriously_how_are_you_all_generating_your_private/dlf4uhr/