Security issues with the design or implementation of Bitcoin and related crypto-currencies.

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2
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1answer
17 views

How secure is calling bitcoind JSON-RPC from same computer?

I am wondering if calling JSON-RPC from the computer it is running on is secure. I read How secure is calling bitcoind JSON-RPC? and understand why it is insecure to do so from a different computer. ...
1
vote
0answers
66 views

Standardize wallet format

What's the status of wallet format standardization? Is there any proposal or work-in-progress around? If not, how come nobody urges to define standard wallet formats yet? This is especially needed ...
3
votes
1answer
62 views

New to Bitcoin - tips on securing my server

I regard myself as being a competent programmer and have good general IT knowledge; however I know very little about BTC. I just want to make sure that my setup is "generally secure" and that I'm ...
2
votes
1answer
44 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 ...
1
vote
0answers
13 views

How do mnemonics encrypt wallet data and what prevents hacking of the algorithm?

How do mnemonics encrypt wallet data and what prevents hacking of the algorithm? For example Blockchain seems to encrypt all data using a mnemonic yet doesn't hold customer data server side. What ...
1
vote
1answer
72 views

How does CryptoNote prevent a 51% attack and double-spending?

How does CryptoNote prevent a 51% attack and double-spending? I’m interested to know what is the mechanism that protects CryptoNote coins from 51% and double-spending attacks.
0
votes
0answers
21 views

Ensure Wallet consistency

I have recently migrated machine. I used the Apple Migration Wizard and when it was finished my new machine's copy of Multibit appears to have my BTC within it. My next task is to wipe the old ...
2
votes
1answer
36 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
votes
1answer
61 views

What are some of the pitfalls of a 100% proof of stake currency (pos) like NXT?

Bitcoin has the vulnerability of a 51% attack for a proof of work currency, but what pitfalls does a 100% proof of stake (pos) currency have like NXTcoin?
2
votes
1answer
81 views

Bitcoin security, what is wrong with my thinking? [duplicate]

Lets assume I keep generating random public keys with their matching private keys and never use them. Severals years later I am checking for positive match against the blockchain for all my generated ...
6
votes
2answers
146 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: ...
5
votes
4answers
2k views

Supermajority to prevent 51% attack?

I would think that amending the bitcoin protocol to require a supermajority, say 60% or 75%, to verify proof of work help reduce the risk of a 51% attack. If this is so, what are the major obstacles ...
0
votes
1answer
98 views

How is Coinbase any different than Mt Gox?

Apparently Coinbase handles the private keys for your wallet which allows them to easily handle buying and selling. As Coinbase is a hosted wallet, we do not provide users with their private ...
1
vote
1answer
81 views

How likely are key pair collision attacks? [duplicate]

Is it possible to be profitable by developing a collision application that continually and automatically generate a key pair, check for the existence of the public address in the block chain, and then ...
0
votes
0answers
32 views

Can't get armory to work

When I try running armory, it seems to download the block change and actually gets to 0 blocks, but then all of the sudden, armory disappears. Anyone know why this is happening? In the log file, I ...
2
votes
0answers
26 views

How are mutated transactions prevented from getting relayed?

Github release notes: ...transaction rules [are] tightened to prevent relaying and mining of mutated transactions... Since the mutated transactions are "equally valid", how does the client ...
5
votes
2answers
130 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?
2
votes
1answer
49 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 ...
1
vote
2answers
261 views

Is the denumerability of private keys a threat?

Since the set of all private keys is denumerable, it is at least possible to create a searcheable record of all keypairs. Which, when finished, is a killer for the whole idea. Am I right or do I miss ...
3
votes
1answer
110 views

Detecting stolen bitcoins?

Is it possible to detect stolen bitcoins? With so many coins being stolen these days, for the more "ethically conscious" bitcoin users, is it somehow possible to check if the coins (you're about to ...
0
votes
0answers
53 views

Multisig transactions vs secret sharing

Some background here, I am implementing a wallet that enhances security by using smart cards. The card stores a pin protected key but unfortunately cannot do ECDSA signing. There is also a server ...
9
votes
1answer
123 views

Heartbleed bug and Altcoins

Bitcoin recently released V 0.9.1 patching vulnerabilities from the Heartbleed bug, however I have not seen anything from any alt coin. What are the possible security risks associated with using these ...
9
votes
5answers
292 views

What would a new exchange need to be better than the rest?

If a new crypto v crypto exchange were to be built and launched. What would tempt you to use it rather than what you currently use? Or what improvements would you like to see from the way things work ...
2
votes
2answers
204 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 ...
0
votes
1answer
67 views

What are the methods for getting an old, used windows P.C. ready for secure Bitcoin usage? [closed]

Let's say I am about to set my Grandmother up with a wallet. I have no idea what she has on her computer. There could be a host of malware, keyloggers etc. Let's also say that a complete wipe and ...
0
votes
3answers
94 views

Does Bitcoin's SHA256 proof make a 51% attack more likely?

Ethereum's description says that Bitcoin's mining algorithm requires only a simple SHA256 computation, which caused the creation of specialised ASICs, which centralizes mining in the hands of a few ...
0
votes
3answers
167 views

TorBrowser + HTTPSEverywhere Blockchain.info wallet safe?

I seem to find conflicting information regarding the possibility of a TOR exit node stealing my data even while using HTTPS. How possible/likely is this? Let's assume user implements strong security ...
1
vote
1answer
157 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 ...
0
votes
0answers
19 views

Proof of solvancy [duplicate]

Andreas has been talking a lot lately about proof of solvency as it pertains to any company that takes custodial custody of bitcoin funds. As someone who's planning to launch a project that does just ...
0
votes
1answer
91 views

Couldn't an attacker cause online (watch-only) wallets to display malicious receiving addresses?

If I understand correctly, one of the main perks of using a deterministic watch-only wallet is the ability to generate new receiving addresses without syncing with the offline wallet, but this seems ...
0
votes
1answer
107 views

Paper wallet generated client side and off network is not necessarily secure [duplicate]

One would think that if a person generated a private key client side and never exposed that key to the internet, that they would be secure. However, the risk is that the paper wallet generation code ...
2
votes
2answers
168 views

mtgox failure… any implications for bitcoin/ecurrency protocol design?

last heard, estimates are Mtgox lost about ~$½B ... apparently the current bitcoin market cap is around ~$8B ie Mtgox failure roughly somewhere around 1/16th the entire market cap of bitcoin, a ...
0
votes
2answers
162 views

Safest method while actually logging in and using blockchain.info wallet

Please help. I have finally set up my cold storage system for but I am too paranoid to login to blockchain.info wallet to send the funds out. Let's assume the account is safe and protected from most ...
1
vote
1answer
77 views

What is the function of the payload_checksum field in the Bitcoin protocol

According to the protocol specification at the Bitcoin wiki, each message header includes the first 4 bytes of sha256(sha256(payload) as a packet checksum. I suppose this checksum is used for packet ...
2
votes
2answers
159 views

What other currencies have same malleability vulnerability as Bitcoin? [closed]

Malleability of Bitcoin protocol has contributed to major losses and represents uncomfortable risk to Bitcoin investors in addition to possibility of 51% attack that depends on promise of biggest ...
2
votes
3answers
216 views

Does the Mt Gox attack constitute theft of Bitcoins or just a Denial-of-Service attack?

What's being reported on the news is that millions of Bitcoins were stolen from Mt Gox. But the Bitcoin Foundation blog says something different: https://bitcoinfoundation.org/blog/?p=422 ...
3
votes
2answers
910 views

How safe is my USD deposit at Bitstamp?

With Mt.Gox probably going insolvent/broke in these days, how safe is my USD account balance with Bitstamp? Is Bitstamp as a company registered with some financial institutions? Are customers USD ...
5
votes
2answers
220 views

Is there a way to stop a man-in-the-middle attack when communicating addresses?

Let's say you have person A who wants to pay person B. A common way for B to communicate his/her address to A is by QR code or email or some such non secure method either of which could be ...
2
votes
1answer
265 views

Does it hurt the network to reuse addresses?

There is already a question that ask why you shouldn't reuse addresses, but it's about whether or not it's a bad idea for the person who would do the reusing. I understand there are several reasons ...
2
votes
2answers
300 views

At what point does the criminal get caught?

Settle an argument for me. Assume a criminal does the following: 1: goes thru trash to find a cancelled check 2: using a wifi hotspot like McDonald's and "Hide my ass" buys bitcoins with stolen bank ...
0
votes
2answers
50 views

bitcoin wallet validation/vetting

Is there any validation service that tests/validates/vets wallet implementations? I use bitcoin-qt on the desktop and I'm not worried about that wallet, I assume it's been well vetted, but if I were ...
4
votes
1answer
57 views

Can ISP intercept network messages to identify the IP of the transaction issuer?

Suppose my ISP is intercepting the bitcoin protocol communication. By analyzing traffic in the network, he could be able to determine that some transaction propagates from my IP (as there is no record ...
1
vote
1answer
131 views

What trust am I placing where when I use Electrum?

I have read that Electrum never is given your private keys (which makes sense), but I'm still unsure what sacrifices it makes in order to not require you to not store the entire ~14GB blockchain. So ...
2
votes
2answers
150 views

is transaction malleability a threat to my local wallet?

I have a local Bitcoin-QT wallet. Can transaction malleability be used to steal my horde of tens of thousands of Satoshis?
3
votes
1answer
754 views

How to download bitaddress.org to use offline?

The site does not have a download option. I can save the page using Google Crome by CTR-S, but the version I have saved in this way does not work.
1
vote
1answer
146 views

How would you store a bitcoin wallet for a small bitcoin exchange?

How would you store a bitcoin wallet with the security of the wallet being a priority for a small bitcoin exchange? Offline wallets are the safest though how would a client be able to withdraw their ...
0
votes
2answers
264 views

Should I keep my bitcoin-qt wallet running all the time?

It can take a day or more to get in synch, so it's somewhat problematic to only start it when I want to transact. But are there any security issues in keeping it running constantly? What's the ...
0
votes
1answer
46 views

Are Web Wallets Secure?

I normally keep only small amounts in a web wallet because I heard that web wallets are not secure. The rest of my Bitcoins are kept in cold storage in my safe. I'm just wondering if you have any ...
1
vote
3answers
80 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): ...
0
votes
2answers
197 views

Are pseudo-random number generation algorithms good enough to cover all possible Bitcoin addresses?

Part of why Bitcoin works is that it's completely unlikely for someone to end up with the same Bitcoin address. But since Bitcoin address generation is based on pseudo-random generation it raises the ...