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Questions tagged [security]

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

20
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3answers
10k views

Is Each Bitcoin Address Unique?

I am wondering whether each bitcoin address is unique. I would assume yes. Then how is this enforced (distributed address generation)? As I understand it each time, an address is generated a new key-...
7
votes
2answers
2k views

Is a bitcoin address collision possible if generating 90 million addresses every 4 hours?

I am running a test to see if I can obtain a successful bitcoin address collision after generating billions of addresses. I am not entirely sure how I would check them yet. Basically I have an extra ...
6
votes
2answers
202 views

Can a full node provide a bogus block bloomfilter to a Neutrino node?

When a thin client using BIP157/BIP158 (Neutrino) requests the block filter for the latest block, would it be possible for the full node serving this request to attack the Neutrino node by providing a ...
0
votes
2answers
55 views

How could a lightweight wallet determine the validity of 0-conf transaction?

I found that a lot of people are interested about security of 0-confirmation payments. But, it seems that most discussions focused on double-spending (like broadcasting two or more conflicting-but-...
13
votes
1answer
2k views

What is the origin of insecure 64-bit nonces in signatures in the Bitcoin chain?

In Biased Nonce Sense: Lattice Attacks against Weak ECDSA Signatures in Cryptocurrencies Joachim Breitner and Nadia Heninger use a lattice based algorithm to recover private keys from signatures in ...
3
votes
2answers
2k views

I think my bitcoin wallet was hacked. What to do?

I opened bitcoin-qt after not mining for a couple months and found that I suddenly have no more bitcoins! And I see that there were 2 transactions that I did not authorize sending my coins to other ...
1
vote
1answer
50 views

Security of Bitcoin Wallet

I have a doubt on Bitcoin wallet. Suppose I have an online Bitcoin wallet. Now, someone breaks into my computer and steals my Bitcoin wallet. Fortunately I have a backup of my wallet on another ...
3
votes
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?
4
votes
1answer
163 views

Lightning Network: asymmetry in the information tracked by each participant?

In following paper, written by Christian Decker et al., there is a paragraph that is not clear to me. eltoo: A Simple Layer2 Protocol for Bitcoin "The central idea of Lightning is to invalidate ...
1
vote
1answer
48 views

Security implications of removing CHECKSIG in a test

If I conduct an htlc transaction on testnet that does not include OP_CHECKSIG will it still cost an attacker more than (say) $10 in processing power or storage to subvert my tests? Details: I'm ...
1
vote
1answer
182 views

Who decides what the next, correct Nonce is?

As I understand finding the correct Nonce is the basis when hashing transactions for Proof of Work. How and where is this decided in the ecosystem what the next Nonce is? In my limited understanding ...
0
votes
2answers
30 views

Physical bitcoin vs. Paper wallet?

What is the main difference between a Physical bitcoin and Paper wallet ? And which one is more secure ? And why ?
1
vote
2answers
206 views

What are the drawbacks of using a web based wallet and how to overcome that?

Can anyone tell me why many prefer to use application when compared to web based wallets. What are the drawbacks of using a web based wallet and how to overcome that?
6
votes
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 ...
0
votes
1answer
130 views

Why are the inputs of Bitcoin transactions signed?

This is my understanding of what a transaction looks like: inputs: input0: txid: <funding tx0 TXID> outputID: <output ID of UTXO in the funding tx0> scriptSig: <...
0
votes
2answers
52 views

What Happened 12/30/17 Last Recieved Transaction into Bitcoin Core Wallet

I have found a different receiving address within my wallet that is not mine... at least I did not create it. It seems to me that all of my transactions are now going to this new address instead of ...
0
votes
1answer
57 views

How does using a Turing-complete programming language compromise the security of the network? [duplicate]

I have read many places that the decision for Ethereum to use a Turing-complete programming language sparked a lot of concerns over security. From my understanding, not using a Turing-complete ...
1
vote
2answers
1k views

Is it possible to bruteforce the seed?

Is it true that the "seed words" bruteforce more reliable for to get profit than searching of a "random number" for to open some profitable outputs? The last one is impossible due to math, but the ...
1
vote
1answer
49 views

Bitcoin Mixing? Is it even real?

I have been trying to find a "bitcoin mixing" service but it seems that ALL the "bitcoin mixing" sites I have looked at are scam. Does anybody know of any that are actually real and do what they say ...
2
votes
2answers
192 views

Exact definition of “Liveness” and “Safety” properties in a consensus?

Two main properties of a consensus are "Liveness" and "Safety". What are the exact and precised definition of "Liveness" and "Safety" properties in a consensus ? Are the following definitions ...
1
vote
0answers
43 views

Why Spectre has a “weak” liveness?

According to this article: (https://medium.com/@avivzohar/the-spectre-protocol-7dbbebb707b5) written by one of Spectre's author (Aviv Zohar), it is mentioned that Spectre has weak liveness. What is ...
1
vote
0answers
95 views

Sybil attack with IOTA?

IOTA is one of the DLTs uses DAG (Directed Acyclic Graph) as data structure. The solutions to attacks proposed by IOTA white paper seems unconvincing, in particular, in case of double-spending, it ...
7
votes
2answers
625 views

What alternatives are there to hardcoding checkpoints into the Bitcoin client?

Checkpoints seem like a crucial part of the security & validation apparatus in Bitcoin. Is there a written policy in place, among the developers defining the maximum interval between checkpoints? ...
6
votes
2answers
1k views

Can you mine without transactions?

As far as I know, mining means verifying transactions and thus keeping the Bitcoin network alive. Today, at a local meetup, some people have informed me that mining doesn't need transactions. They ...
4
votes
1answer
383 views

Why was an insecure merkle tree implementation chosen?

At risk of creating a "lets discuss politics" question, let me clarify that what I want to know is whether there is a known benefit to Satoshi's "duplicate the last hash" merkle tree implementation ...
0
votes
1answer
41 views

Does Electrum store my seed in their server?

I am new to Bitcoin. I used Electrum software to create my first wallet. When the software generated 12 words, I had written down that in paper. These word are very important, right? But the software ...
1
vote
1answer
57 views

Is the statement that LN hot wallets will be less secure than non LN hot wallets correct?

I say this because of the following reasoning: Lightning network wallets will have to completely possess my private key, whereas non-LN hot wallets will most of the time only have my key encrypted (I ...
6
votes
3answers
4k views

How to generate a public key from a private key using Elliptic Curve Digital Signature Algorithm

I'm trying to understand the graphical basis that underlies the discreet logarithmic Elliptic Curve Digital Signature Algorithm (ECDSA) introduced in Chapter 4 of "Mastering Bitcoin" by Andreas ...
0
votes
2answers
29 views

Hiding identity in digital currency era

I have a question about the security of digital currencies, however still I have find a clear answer for that. No matter what is the currency, e.g bitcoin, monero, ..., at the end of the day, I have ...
8
votes
1answer
1k views

What is BlitCoin?

I saw BlitCoin mentioned on this forum thread, but didn't understand what it was. Can someone explain what does it do?
130
votes
8answers
47k views

What can an attacker with 51% of hash power do?

Suppose organization X has 51% of the hash power for a period of 1 week. In this week, what exactly can and can't X do?
0
votes
1answer
75 views

Why can a wallet not compute the private-key from a public-key?

my goal of questions this is why any wallet not able to compute private key created with public key generate?
1
vote
1answer
30 views

What would happen if I publish a modified version of an earlier block? Would it be rejected immediately by peer nodes?

I am reading the book "Mastering Bitcoin" and have finished reading Chapter 2 and 10, but I still don't find the answer. Suppose the current main chain has 5 blocks: B0 <- B1 <- B2 <- B3 &...
4
votes
1answer
665 views

What happened to my coins, hacked?

I'm new to bitcoin, downloaded the bitcoin.org client, encrypted my wallet, and purchase a few bitcoins (5.25), for learning purposes. But now my coins seem to have disappeared to an unknown address. ...
1
vote
1answer
50 views

Have there been any examples of people manipulating transactions in a way that waiting for more than 1 confirmation would avoid?

A lot of bitcoin exchanges require some minimum amount of confirmations before they consider money deposited. Is there any evidence that this actually does anything? Has someone ever before ...
0
votes
2answers
243 views

Address reuse, one address per person

I know about the privacy and security implications of address reuse. But I was thinking about a scenario where I have one address for every person I receive transactions from. This would still have ...
1
vote
2answers
50 views

Can't understand specific problem of Bitcoin anonymity

There is an problem shown in bitcoinwiki: Someone runs both a money exchanger and a site meant to trap people. When Mr. Doe buys from the exchanger and uses those same coins to buy something ...
2
votes
1answer
89 views

Can I, and should I, verify bitcoin core source code before compiling it?

If I use bitcoin core binary release I can verify them with the gpg keys of the core developers. Is there a similar process for the source code? A follow-up question: Is it preferable to use signed ...
2
votes
2answers
392 views

What can you do with the private key?

I am trying to understand all security regarding blockchain and bitcoins. Let's say you have a bitcoin wallet which is secured, only you know the private key. This bitcoin address was created on one ...
1
vote
1answer
27 views

Review sites for the hardware wallets? [closed]

As I understand it there are four (4) hardware wallets produced currently (2018). Which businesses, web sites, or academic papers in the field review and compare the security of these devices? Is ...
3
votes
1answer
125 views

A couple of questions on Schnorr sig

In the BIP by Pieter Wuille it is told that the key prefixed version of Schnorr signature is needed when the scheme is used in combination with BIP32's unhardened derivation. Could someone provide an ...
5
votes
3answers
280 views

Bitcoin value vs. Supercomputing

What protects the stability of Bitcoin's value if supercomputers or some other technological breakthrough allows them to be mined at rates we have not anticipated?
5
votes
1answer
686 views

What precautions should be taken to protect a Ripple wallet?

What if a Ripple wallet gets hacked? What are the suggested precautions for the average user?
1
vote
1answer
404 views

How many peers do you need to securely synchronize with the blockchain?

What is the minimum number of peers required to securely synchronize my local blockchain copy?
4
votes
3answers
11k 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 ...
0
votes
2answers
208 views

How can address' hash160 be used to determine information for malicious purposes? (Ie reusing of the same address)

I've been playing around with Richard Kiss's Pycoin app which is clarifying how P2PK works. I see that the hash160 of the value: (0x04) (x-coordinate) (y-coordinate) (for an uncompressed Testnet ...
1
vote
1answer
421 views

How to store private key in MySQL database?

I want to receive payments from Bitcoin on my web app, but I do not want to use corporate gateways (coinpayments, bitpay, etc), I'm wanting to make my own gateway. I do not know how best to do this ...
2
votes
3answers
1k 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
vote
1answer
68 views

Delegated Proof of Stake (DPOS) vs. Proof of stake?

What is the main difference between Delegated Proof of Stake (DPOS) vs. Proof of Stake? Is there any significant advantage for security? (since PoS in general suffers security problems.) And which ...
0
votes
3answers
529 views

Is creating a long password for my coinbase account enough to keep my bitcoins secure?

I've made an account with coinbase and purchased some bitcoin. Only after to start reading people talk about getting hacked and how bitcoins are not secure unless you put them in a "wallet".To be ...