Bitcoin Forum

Is Blockchain.info safe  ? for 15 BTC +  ?

Are you referring to blockchain.info?

If so, no, they can't.

If your bitcoins are in your own wallet then they cant be stolen unless someone has your details/hacked your account. you should be fine.

If you use them for their wallet service they can and they don't need a reason.

If OP is talking about the actual blockchain:
Bitcoin is decentralized and if you're doing things correctly, only you can control your funds.

They can easily feed you malicious javascript when you are logging in so your password goes to them instead of decrypting it in your browser.
So, yes, they could.

If your running a bitcoin casino, the best way to keep funds safe is to use cold storage wallets that are generated on a computer that is never connected to the internet.  If you google search, "Cold Storage" there will be many sites detailing how to make one.

How can they scam the users when we own the private keys of our wallet? There are thousands of users who use their online wallet and I've not seen users complaining about their wallets getting froze. Many have reported that they have lost access to their accounts due to loss of private keys.

Bear in mind that it is pretty easy to make what appears to be an online wallet service.  When the site generates the receiving addresses it can maintain control over them and simply transfer the whole lot to themselves when the time is right.  Stick with the ones that are well known.

They can take your bitcoin since they own the private keys like you.
It is not likely to happen since they have become a respectable company these days.
Not some anonymous person from the east of europe for example.

Your question is not clear .
The actual Blockchain has all bitcoin transactions that happened and will happen. Every one uses bitcoin core wallet has that blockchain on his computer. So block chain technology is very safe.

If you mean blockchain .info wallet , I'm using it without any problem. It is well known company and has a great reputation

They can, but i don't expect them to do that.

But, never keep too many coins with a third party. Bitcoin is made to be safe with your OWN local wallet. There is no need to only use third parties. In fact it is even dangerous.

^This. They haven't until now (or maybe they have?) does not mean that it safe or that they can't/wont in future. If you must use blockchain.info's wallet then just use it for petty cash for day to day activities, if you use it for larger amount of funds then you're just asking to get robbed and it might happen one day.

No if you are referring to blockchain.info they are safe and secure till now and i don't think they will steal in future too.
If you feel unsecure make cold storage address on blockchain.info and put all of the coins there, don't forget to print out the cold wallet paper you get there as .pdf file.

In that case, any wallet provider can do that, including Bitcoin Core.

Yes. However there is an additional question.
Can they get away with it with nobody being able to prove they did it and have 1000 users even proving that they did not do it?
And is it possible that only one possibly some shop floor level server operator can do the stealing with nobody else even some higher up from the company knowing about the theft and who did it.

For an online wallet the answer is yes, trivially.
All they need to do is for one time feed the malicious javascript to one user only which they have selected to be the one they want to steal from. The probability that everybody inspects their javascript EVERY TIME they use the online wallet is just ridiculous.
Clean up the server and nobody knows what happened with no proof available to anybody and blame a keylogger in the victims computer.
Have 1000 users inspecting THEIR javascript to "prove" that the javacsript from the company is safe with no backdoors.
Has that happened already? You betcha.

For bitcoin core the answer is no.
The proof about the malicious code remains out there forever and traces about who put it in there.

With bitcon core it would be very hard. So many geeks are using those wallets, scanning them etc. etc. theyr suprise back door or virus will be hot news within a few hours.
Blockchain.info is 'watched' by far less many geeks. But I don't expect them to do something like that.

However, i never hold more then 1 BTC with either blockchain or coinbase.

there were some holes in the past but many of them are fixed, now, what can really steal your coins is a infected computer, nothing else

so remember that when your coins has been stolen, it was 100% your fault if use a local wallet, and let's say 50/50 if you use a web wallet...

I doubt if they can do that you own the key to that  it goes up on how you manage that properly I have read that many people lost their bitcoin but not because of blockchain but because of their negligence you can do a cold storage if you want to really keep your bitcoin in a very safe place

If you are asking about Bitcoin's general "block chain", then you don't need to worry about anything because, a block chain is a transaction database shared by all nodes participating in a system based on the Bitcoin protocol. A full copy of a currency's block chain contains every transaction ever executed in the currency for it's decentralized outlook. You can view the live block chain here (https://bitcoinchain.com/block_explorer).

In case you're asking about Blockchain website (https://blockchain.info), then I would advise you to check the various ways to access (https://blockchain.info/wallet/ways-to-access) your wallet there and the security characteristics associated with each types.


In this case, you can chose your preferred wallet (https://bitcoin.org/en/choose-your-wallet) after studying the various security measures it can enhance while keeping your funds safe.

One pro-tip for running a Bitcoin casino; use two different wallets, one as a cold wallet for reserving 70-75% of your bankroll and another one as a hot wallet for running your games.

Again, in that case any wallet can be used, including Bitcoin Core.

im going to read you comments now

Yes. HOWEVER, Blockchain.info is an online wallet. It downloads resources from a third party source. Unless you audit the code every single time you try to log in, there is no sure way. Bitcoin Core on the contrary, requires users to download the malicious code in order for them to steal the Bitcoins.

There is another possibility however. Unless you are using a strong password, they can easily bruteforce your wallet backup based on a dictionary wordlist. I'm not sure of the encryption used, that is a problem if its weak.

That being said, Blockchain.info being an online wallet can also:
Weaken the RNG such that private keys are predictable[1][2]

[1] https://blog.blockchain.com/2014/12/08/blockchain-info-security-disclosure/
[2] http://arstechnica.com/security/2015/05/crypto-flaws-in-blockchain-android-app-sent-bitcoins-to-the-wrong-address/

With those knowledge I can only advice to use your webwallet for small and fast transaction.
Your offline wallet should be used to store large amounts of bitcoin.
Remember to back it up every week or so.

Yeah obviously man! Haven't you seen their stats page ? They have more than 10 btc transferred like every minute I guess.I have been using blockchain for about a while now and never had any issues with them except the technical issues they keep on having during their updates .

If you are using this all as correctly and controlling your Private keys then they cannot steal your bitcoins I am in this field for 3 years and I never have any issue like this so its very safe to work with them

I think they can if they wanted to, they do say that they don't know the keys and that they're generated completely on the user side but I don't believe that. And they did somethings wrong before which got them removed from the "Choose your Wallet" (https://bitcoin.org/en/choose-your-wallet) list, so that should be enough to make people understand to not use their wallet or if they must, just keep as minimal funds there as possible.

Can you edit the subject because it's correct "Can blockchain.info steal our  bitcoins?"

By the way I think they don't have any earning from this.

No they can't. Blockchain.info provides the customer an online wallet but the customer is always the one who as full control over the wallet and the only one with access to the secret key.

Did you even read the previous posts?
Blockchain.info relies on javascript in your browser to decrypt your wallet.
Most users (probably 99.999%) don't check the javascript for blockchain everytime they log in.
And for the users that do it, they probably are so security conscious they wouldn't use an online wallet in the first place.
What you said is true though other than the No they can't.
Blockchain encrypts your keys so they can't read them, but they can easily change the javascript and send the password to their server. Then they can decrypt it there.

No it will not steal your bitcoins even a decades but if your account password get by stealers or hacker
your account will be hack and your bitcoins will gone. So place your private key to your brain or some folder with lock
Your wallet will be secured..

You are not reading the posts.
Blockchain.info wouldn't do that otherwise their reputation will be ruined. No one will use their wallet. The previous flaws detected in blockchain.info was code bugs, which was explored by the hackers.