Questions tagged [security]

This tag should be used for questions regarding security issues with the design or implementation of Bitcoin and related cryptocurrencies.

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5
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1answer
209 views

Is bitcoinica.com planning to reopen after the 11th May 2012 theft?

On 11th May, 2012, 18,547 BTC were reported stolen from bitcoinica.com as stated here: https://bitcointalk.org/index.php?topic=81045.0 The bitcoinica.com website is unresponsive at the time of ...
4
votes
1answer
741 views

Is JavaScript wallet generator available at bitaddress.org relatively secure?

I wonder if it's safe to use JavaScript generator available at bitaddress.org. Even if I'll generate it offline, how can I know if the algorithm is not using any pre-computed / pre-planned way of ...
4
votes
2answers
1k views

What has a lower long term cost per hash: LTC, BTC or other alt coin?

I'm trying to understand the cost per hash operation with Litecoin vs Bitcoin over time. The theory is that the network that has the best prospects for long-term security (via hashing) will set a ...
4
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1answer
578 views

Lightning network and lightweight clients

How will the lightning network handle lightweight clients? Do I understand it correctly that opening a payment channel require writing on the blockchain to protect against double-spend? The integrity ...
3
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1answer
213 views

Can I detect a 51% attack as a developer

I am a developer building an application that accepts payments in cryptocurrencies. Is it possible, in the occurence of a 51% attack, to build a script that detect this, so we can suspend withdrawals ...
3
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3answers
323 views

if my wallet is sufficiently secure, can I ever lose my coins?

I've made an offline address and only have the key stored on 2 encrypted flash drives stored in different locations with the private key written physically on paper and stored in 2 locations. Do I ...
2
votes
1answer
392 views

Are lightweight LN wallets vulnerable to transaction withholding?

As far as I know, LN requires the user to watch the blockchain in order to perform penalty in time. However, running full node is probably a heavy burden to some users, especially to mobile phones. I ...
2
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2answers
1k views

MultiBit Password Protection - How Secure is it?

I'm new to BitCoin but a friend of mine was recently stung when a bunch of his coins were stolen. Naturally, I'm now very cautious. I've password protected my MultiBit wallet and, to test the security ...
2
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1answer
3k views

Who can see my IP address while using Electrum

Who exactly is my IP exposed to when sending transactions in Electrum. I'm assuming the server operators can see it every time I connect (to query the servers about my balances). When I make a ...
1
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1answer
327 views

How to protect against wallet theft?

Let's say I run a Bitcoin client on a computer (Windows, but the question can apply to other O.S.es too), and I want to make sure nobody steals it. I'm especially concerned about situations where ...
0
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1answer
503 views

What are the advantages of running a full node in comparison with a lightweight client?

I read that running a full node provides "more security" than running a SPV client. What does this concretely mean? I think I understand pretty well how those two kinds of nodes work but I do not see ...
13
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3answers
4k views

Should I trust bitaddress.org?

AFAIK, the generation of the address pairs occurs on your computer but the concept still makes me nervous as it's occurring in the browser and I have to trust the owner of the site, I think.
10
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1answer
2k views

Bitcoin automatically diverted to bech32 address

I sent bitcoin to an address starting 3Cn using Electrum but the blockchain viewers seem to show that it has gone to an address beginning bc1 as shown in the link below. Transaction Viewer How can ...
8
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1answer
667 views

What is the “1 RETURN” bug?

From Nathaniel Popper's “Digital Gold : Bitcoin and the Inside Story of the Misfits and Millionaires Trying to Reinvent Money", this heavily edited (by me, for clarity) excerpt: “In late July Gavin ...
7
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2answers
1k views

Has someone compared the cost of mining vs. that of brute-forcing addresses?

It is known that the type of computing power required for mining is the same used to generate addresses, and it is known that "in general" it is much more profitable to simply mine, rather than try to ...
7
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2answers
185 views

Does GHashIO already have above 51% hashrate?

Right before writing this question I noticed the GHashIO showing 32% hashrate distribution using the following link. Unknown has 26%. And the IP address of the most blocks reported from unknown is: ...
6
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1answer
1k views

Why is increasing block size in the Bitcoin network considered to decrease security?

I have been doing some research on the Bitcoin Cash hard fork and the main contention of increasing the block size appears to be the possibility of less security on the network. How does an increased ...
5
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2answers
162 views

Will Bitcoin scaling affect the amount of hashing power required to keep the network secure?

In Mastering Bitcoin Andreas Antonopulous asserts that "Bitcoin can scale up, achieve broader adoption, and remain secure without any increase in hashing power from today’s level." Is this really ...
4
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4answers
5k views

Did I just create counterfeit bitcoins?

I had 3 Bitcoins stored on my PC and I had a backup image of my PC. I restored my PC on another computer from the image and I had 3 Bitcoins on that computer also. I spent 5 Bitcoins as a test, and it ...
4
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2answers
291 views

Can bitcoin node startup be secure without validating the entire blockchain?

One of the largest hurdles in my mind to increasing the number of full nodes operating is the startup cost related to downloading the blockchain. A similar but less important (in my mind) issue is ...
4
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3answers
12k views

Can we report a fraudster by their bitcoin wallet address?

I was recently notified by a friend that someone sent her a message (posing as me) on an app asking her to send them some bitcoin so they could make a purchase. Luckily she knew it was not me and let ...
4
votes
1answer
310 views

Why is a chain code needed for entropy in HD wallets?

In the documents and articles I have read, it is stated that the "chain code" in HD wallets exists to provide entropy to the derivation of child public/private keys. If I understand the process ...
4
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6answers
2k views

Why are brain wallets not secure? People keep saying it, but explain to me why?

Everyone keeps saying brain wallets are insecure. Can someone explain to me WHY? What if I had a brain wallet that is 200 characters long which is the concatenation of all of my family members names ...
3
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2answers
356 views

What is it about a Trezor that means it can't be infected by malware?

The Trezor testimonials include that TREZOR ... cannot be infected by malware What is it about a Trezor that means it cannot be infected?
3
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2answers
149 views

Is possible to destroy the Bitcoin for just $500K? (51% attack)

Everytime I read about the 51% attack the answer was something like: is really expensive to get 51% of power on BTC and nobody will invest so much so to destroy the bitcoin. But I found this site ...
3
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1answer
254 views

Can side chains or “pegged” chains negatively affect the security of Bitcoin?

Regarding the concept of side chains or "pegged" chains which has been discussed since as early as 2011 and explored in this white paper, how can these negatively affect the security of Bitcoin? ...
3
votes
1answer
327 views

What is Mt. Gox's YubiKeys' “configuration protection access code”?

Does anyone know if Mt. Gox, now that they're bankrupt, has released their YubiKey's "configuration protection access code" (cf. this)? If so, we could reprogram the free YubiKeys they sent us and use ...
3
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2answers
1k views

What security threats does blockchain technology solve or present?

I am interested in security, identity and authenticity in electronic networks. What sort of security concerns could blockchain technology help with and what sort does it pose? Are there entry and ...
2
votes
1answer
532 views

How to securly move bitcoins from a wallet.dat file to a paper wallet? [duplicate]

I have an old wallet.dat file with a few Bitcoins. It is stored in an isolated computer that is not connected to the internet. I would like to get rid of the wallet.dat file, and move all the ...
2
votes
1answer
217 views

Where can I look to see a revealed public key?

I've read that pub keys aren't exposed until they're spent from. Can someone show me an example of a transaction prior to the pub key being exposed and then after? Where do i look?
2
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2answers
631 views

Can a Trezor seed be used in any other HD wallet?

Trezor FAQ says If you do not use a passphrase, your recovery seed is all that is needed to access your bitcoins. If you do not use a passphrase, can the Trezor seed be used to recreate a ...
2
votes
3answers
247 views

Is there any study or research of how to make BTC transfers refundable?

is there any study or recent research of making the bitcoins transfer refundable? As if your account is hacked and the bitcoins are transferred there is no way I can return it back.
2
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1answer
249 views

BIP 38 Implementions for Altcoins?

Trying to identify implementations for creating BIP 38 encrypted private keys for alternative coins to spark collaborative open source discussions to standardize BIP 38 to support altcoins. Please ...
2
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1answer
212 views

“Instantaneous” transaction verification?

Jan Moritz Lindemann graciously educated me that difficulty is used not only to regulate the creation rate of a cryptocurrency but also to allow for block propagation thus prevent orphaned blocks. ...
2
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3answers
2k views

ECDSA x,y coordinate validity verification doesn't seem to work

The ECDSA algorithm, secp256k1 for Bitcoin allegedly uses the equation y ^ 2 = x ^ 3 + 7 mod P to determine the validity of an alleged point upon the elliptical curve. Utilizing http://web2.0calc....
1
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3answers
174 views

What is the role of bitcoin wallets?

I'm trying to get involved in bitcoins, but first it seems I need further clarification on the concepts involved in bitcoins. First let me clarify what I know (at least what I believe to be correct): ...
1
vote
2answers
278 views

Why don't the miners just take profit from our coins and make the coin worthless?

You own a very valuable thing and you want to go to holiday without it, but there is nobody who you trust and who can look after the thing. So you take somebody unknown to guard it. You pay him a fee ...
1
vote
1answer
115 views

Can a double spend attack be obfuscated by mimicking the transactions seen before the fork?

An attacker controls the majority of the hashing power and wants to double spend without arousing suspicion. If they mirror the public chain's activity while generating the private fork and the fork ...
0
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1answer
118 views

How would one go about acquiring the HashofThingtoSign from this old transaction?

How would one go about acquiring the HashofThingToSign that is used in the "Signature Generation" equation for this example transaction such that it could easily also be applied to any other given pre-...
0
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1answer
265 views

Purpose of difficulty?

Is the purpose of difficulty only to manage the rate of a cryptocurrency's creation, or should difficulty also increase over time to compensate for Moore's Law for a consistent level of security? ...
0
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2answers
320 views

Private key security level

Any of a kind Bitcoin wallet need to share private key on the internet-connected machine. Bitcoin client has no responsibility for to keep private key secure. If your's machine connected to the ...
0
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2answers
102 views

i lost access to my bitcoin [closed]

I did not have any idea about bitcoin but I wanted to get in, I met this guy who knew about it on facebook asked him if he could help. he sent me the link on blockchain to signup showed me how to buy ...
-1
votes
1answer
234 views

I transferred BTC from mtgox and they have disappeared - What should/can I do? [duplicate]

I sent 3 btc from mtgox to cavirtex. The address used is correct and I was given a transaciton ID by mtgox. Yet blockchain.info shows no record of a transaction and 3 btc are missing. I have written ...
-1
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3answers
422 views

Is it as easy as buying 1BTC and leaving it in a wallet? is there anything else to “Bitcoin investment”? [closed]

Just as title says, I always hear about BTC lately and want to get in on it, or is it too late?
-2
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2answers
210 views

Catching thieves: Network Jury? Account blacklist? Additional TX script commands? [closed]

When someone steals 25,000 BTC from a single user, everyone on the network can just watch the coins move around the public ledger, but no one can do anything about it. Can't we do something about it? ...