Questions tagged [security]

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

2
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1answer
23 views

Does assumevalid lower the security of Bitcoin?

Bitcoin's assumption was to download the blocks and verify it in order to prevent getting fooled. But by default, the assumevalid option is enabled in the software, which, as I understand it, makes ...
2
votes
1answer
27 views

Is this a collision attack or a 2nd-preimage attack?

This question revolves around Bitcoin Optech newsletter #51 (1) and an email thread from the bitcoin-dev mailing list (2). I asked the same question in a reply-email of the newsletter and the response ...
1
vote
2answers
45 views

Is it possible to separate blockchain and wallet functions?

I'm looking for a way to use bitcoin-core in monero-way (It uses separate blockchain daemon and wallet daemon). I'd like to run bitcoin-qt interface on my laptop and connect to external node with ...
10
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2answers
2k views

Long term BTC investing

my question is, what is the safest way of buying and holding bitcoin for the long term? And I mean 10-20 years, either a lump sum or through dollar cost averaging, is a paper wallet the answer? Or ...
5
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2answers
547 views

Capturing IP address of transactions submitted to Bitcoin

Dan Kaminsky has pointed out that it would be possible to build a service that tries to infer the source IP address of each Bitcoin transaction. His idea, which he calls Blitcoin, works by ...
3
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2answers
143 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
41 views

How many nodes is too many?

Has anyone done the math on this? For example, if we had 10’s of millions of nodes all connecting to 8 peers would there be some latency issues in propagating blocks across the network in the 10 ...
1
vote
1answer
229 views

What bad things could happens if Bitcoind RPC is public?

It is always suggested to enforce authentication on Bitcoind RPC. However, in case the RPC authentication get compromised (or if it is public), what kind of bad things could happens? First I could ...
19
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6answers
7k views

51% attack - apparently very easy? refering to CZ's “rollback btc chain” - How to make sure such corruptible scenario can never happen so easily?

I was shocked to see binance CZ comment to literally "roll back" the bitcoin chain by just "calling" in some favors from "friendly" Asian miners . This ONE person could effectively do it??? I mean ...
14
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2answers
3k views

How do you derive the private key from two signatures that share the same k value?

I wrote my own ECDSA signature algorithm just for the purpose of creating unit tests. With it I created two signatures which went into transaction 56ec7ca7df..., sending from 1GXFXm3es.... These ...
10
votes
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 ...
0
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3answers
57 views

Bitcoin scam artist

A guy I have been talking to says he is having trouble accessing his account and asked me to make a wallet in blockchain and then wants my login, password, and wallet id so he can use it in another ...
35
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3answers
7k views

What are checkpoints?

I often read that checkpoints protect the network from a 51% attack because an attacker cannot reverse transactions made before the last checkpoint. How exactly does this checkpoint mechanism work? ...
0
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1answer
5k views

What happens to Bitcoin wallet / Bitcoins if PC is stolen

I am a beginner and just starting to explore the possibilities of Bitcoins. So I would be very grateful if somebody could help me with this question. Is there a risk that my Bitcoins are lost if the ...
2
votes
1answer
69 views

How much of the Bitcoin Source code is untouchable? [CVE-2018–17144]

My understanding is that CVE-2018–17144 (inflation bug introduced in 0.15) was partially a result of how convoluted the original code is. Regardless of the specific CVE-2018–17144 example, are there ...
12
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1answer
287 views

Schnorr's batch validation

In the recent BIP about Schnorr's standardization, Pieter Wuille presents an algorithm for batch validation. In my understanding the most heavy operation is the multiplication by a scalar: to make ...
0
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2answers
126 views

LND Security best practices? Disaster recovery?

Can anyone share a knowledge how to _ secure LND node _ backup node with all Channels I think only a seed will not be sufficient. What is your plan B in case of disaster? How to do an Emergency ...
2
votes
1answer
126 views

Lightning network hub security?

Reading the whitepaper, I came across a point: nodes wishing to act as effective intermediaries, 'hubs' or not, need high availability and need to operate autonomously. This means they must have ...
4
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1answer
563 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
65 views

Does LN require an on-chain “emergency lane” to mitigate systemic risks?

According to LN social slides, a fee market (in other word: "congested mempool", to my understanding) is good. But, there's systemic risks around penalty mechanism, so some sort of on-chain scaling (...
11
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1answer
4k views

Why is JSON-RPC over SSL “strongly discouraged”?

The Wiki contains a page that simply states: JSON-RPC over SSL is strongly discouraged Why? I found a method for enabling JSON_RPC over SSL here. The post mentions nothing about JSON-RPC over SSL ...
1
vote
2answers
119 views

Does my Electrum wallet become less secure if I keep generating seeds until I see one I like the look of?

Let's say I want to create a new electrum seed... I didn't like the initial seed words, since I want to remember them and these didn't look too appealing. Looking "too random" for my taste. When I ...
0
votes
1answer
2k views

Private key to mnemonic words, is it safe?

Is it safe to do the following? Suppose I do not want the HD wallet, but I do want the convenience of using mnemonic words to remember the private key. I know I can convert the private key's hex ...
-1
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1answer
42 views

How Spectre tolerates spam transactions?

Spectre is a DAG based (directed acyclic graph) distributed ledger (a structure as an alternative to blockchain based distributed ledger). Is there any mechanism in Spectre to prevent sending spam ...
1
vote
2answers
99 views

What’s the purpose of checking for input overflow?

Everyone knows this famous fix for block 74638 which still exists in other files. But there’s something I can’t understand, why check for inputs overflow since it’s not possible to have enough utxo ...
3
votes
4answers
344 views

Store Bitcoins offline

I have some bitcoins and ether at Blockchain.info and I am really scared of losing them. How do I best secure them? Right now I have a paper with the code to restore my wallet, but my coins are still ...
0
votes
1answer
80 views

Does a HD Wallet log my IP when i do a transaction?

Companies like BitPay and Electrum, can log my IP when I make a transaction, right? If so, should I use a Web Wallet (plus VPN) for transactions?
1
vote
2answers
56 views

Why was noise XK fundamental pattern chosen in the transport layer (BOLT 08) of the lightning network

I am currently reviewing the transport layer of the Lightning network protocol. It builds on top of the noise protocol framework handshake patterns. What I don't get: Why was the fundamental pattern ...
1
vote
0answers
11 views

Does Bitcoin security rely on the assumption of nearly continuous transactions? [duplicate]

So for an attacker not to overcome good nodes, I believe we rely on the fact that blocks are always being produced, making the attacker essentially outpaced. But in the extreme and ridiculously ...
3
votes
2answers
1k views

Make remote RPC connection to bitcoind server secure

I set up a bitcoind server on an Ubuntu server and I can remotely execute commands on the server. I am doing this with Java/RPC. To execute a command I need to provide a username and password. But I ...
0
votes
1answer
35 views

Automatically close the bitcoin-qt when enable SSL for RPC

I Just try to enable SSL for bitcoin-qt RPC call. I follow the SSL on RPC link to archive my target. But I am getting the following error and close the bitcoin-qt automatically. I am using the ...
0
votes
1answer
29 views

How does the Blockchain detect a cheater, who manipulates the blockchain?

Let's assume we have 100 blocks. One miner x has the intention to manipulate block 90. So he has to recalculate the hash for block 90. Following he also has to recalculate the hashes for block 91-100. ...
2
votes
1answer
43 views

Malicious full nodes causing denial of service attacks

To control >51% of the mining power in bitcoin is impractical due to the immense investment that will be required. Also, The Bitcoin Core client has DoS protection against malicious nodes forwarding a ...
0
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1answer
250 views

Are DAG-based crypto currencies as secure as proof-of-work based blockchains?

A key feature of blockchain based cryptocurrencies is that they provide inherently secure systems that don't rely on third parties. The newer DAG-based cryptos like Byteball are being touted as ...
0
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0answers
24 views

secure Multi-Party Computation (sMPC) in Enigma?

In Enigma whitepaper (>> Link to the Enigma paper <<), in section 5.1 "Overview of secure multi-party computation", page 4, explains how to divide a secret s into multiple shares, using ...
0
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1answer
178 views

Hello, someone is using an bitcoin account to blackmail me [closed]

Someone using a bitcoin account is trying to blackmail me. The account number is 1Mtsd3wXgkJnApaNpqaSSWLC6gCLBBxuaGG. I still have the email they sent me. I can also provide that email if needed, or I ...
0
votes
1answer
64 views

Private key generation doubt

I read that the private key pk has to be any number between 1 and n, where n is almost 10^77. Since pk' s function is practically to be used as a scalar for multiplying the generator point G, why does ...
0
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1answer
29 views

Are transactions with the same ScriptSig a security problem?

For instance while looking at the transaction stack of my address, tracing it to exchanges I use, I came across this: https://www.blockchain.com/btc/tx/...
2
votes
1answer
387 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 ...
8
votes
2answers
22k views

Creating a fake transaction

AttackerAlice has a BTC Wallet with 0 BTC. AccompliceBob has a BTC Wallet. Is it possible to transfer 100 BTC from AttackerAlice to AccompliceBob? Suppose a BadMiner accepted this as a valid ...
0
votes
1answer
19 views

Security of ChaChaPoly (IETF rfc7539) in the noise protocol framework of the Lightning Network

According to this paper ChaChaPoly is secure against chosen known plaintext attacks. I wonder however if that security assumption is weakened by a lot since messages sent on the transport layer of the ...
2
votes
1answer
154 views

Byzantine Fault Tolerance Threshold of Bitcoin: 1/2 or 1/3? (Edited)

According to this answer: https://bitcoin.stackexchange.com/a/58908/41513 a Byzantine Fault Tolerant (BFT) consensus threshold is 1/3. On the other hand, there is a common belief that Bitcoin network ...
5
votes
1answer
118 views

Why is the length of the transport messages on the lightning network encrypted?

From BOLT 08 we can see that every message is sent in the following way: 2 byte: length 16 byte: MAC [length] byte: Encrypted message 16 byte: MAC In reality these messages will be send over TCP/...
5
votes
1answer
106 views

Does MuSig have the same security as 2-2 multisig?

Disclaimer: This question is of theoretical importance to me trying to educate myself better on cryptographic principles and signature schemes. I don't intend to imply that in practice schnorr ...
0
votes
0answers
43 views

How may bitcoins hash algorithm be secured in the future from quantum computing brute forcing?

Other threads already answer very clearly that quantum comps could easily "break" /attack bitcoins chain. Now: Are there any ideas among the bitcoin devs circulating out there, how to save bitcoin ...
0
votes
2answers
44 views

If a bitcoin wallet service provider terminates a users account, what happens to the funds?

A friend of mine has/had a bitcoin wallet service provided by an online marketplace. Sounds like he had some kind of disagreement with the site administrators and they terminated his account. At that ...
0
votes
1answer
70 views

Permissioned or Permissionless blockchain? Which one is PoS more adapted for?

Since in proof-of-stake (PoS) there is no mining process, according to functionality of permissioned and permissionless blockchains, which type is PoS more adapted for? In the other words, is a PoS-...
0
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2answers
104 views

How secure is using TOR in Lightning Network?

In following paper (Link to the paper) we read: "combining Tor and Bitcoin creates an attack vector for the deterministic and stealthy man-in-the-middle attacks. A low-resource attacker can ...
5
votes
2answers
597 views

How to perform a double spend attack in websites that accept transactions with 0 confirmations?

To perform a Finney attack or a 51% attack I need to have lots of computational power, but in this case (a website that accepts transactions with 0 confirmations) it seems to me that I only need to ...
12
votes
5answers
3k views

How safe is a brain wallet?

Edit: The answer is that they are unsafe and have been attacked. Please don't use them! Brain wallets can be created with a (minimum 15 character) pass phrase at https://www.bitaddress.org There are ...