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

learn more… | top users | synonyms

2
votes
1answer
14 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 ...
-2
votes
0answers
18 views

Majority attack solution: forcing clients to hash on transaction? [on hold]

Wouldn't a solution to the majority attack (51% attack) be to decentralize the system even more force clients to hash a certain number of transactions when they make one, and not allow them to hash ...
2
votes
1answer
77 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 ...
0
votes
1answer
86 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 ...
0
votes
0answers
23 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
126 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?
3
votes
1answer
107 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
48 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
119 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
287 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
178 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
60 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
2answers
139 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
133 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
85 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
106 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
151 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 ...
0
votes
1answer
64 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 ...
3
votes
2answers
802 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
200 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
215 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
298 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
46 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
54 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
118 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
659 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
136 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
234 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
45 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 ...
0
votes
3answers
75 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
181 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 ...
2
votes
1answer
308 views

Make remote RPC connection to bitcoind server secure

I set up a bitcoind server on an ubuntu server and I can remotly execute commands on the server. I am doing this with Java/RPC. To execute a command I need to provide username and password. But I ...
1
vote
1answer
2k views

How can I restore my dogecoin wallet (android client)

How can I restore my dogecoin wallet backup? It was created by the dogecoin android client and lives in my Google Drive account. This question already exists, but no answer is given for Android (and ...
0
votes
2answers
409 views

How does this OpenCL BTC private-key cracker work? Is it a real threat to bitcoins?

I am specifically referring to this over at bitcointalk.org. The general consensus I gathered from reading the thread is that this is not a hoax. There seems to be a group of generated bitcoin ...
2
votes
3answers
120 views

Any need for coinbase field in coinbase transaction?

My understanding is that every block in the bitcoin blockchain has a coinbase transaction which contains a coinbase field. It is essentially an orphan field (placeholder) for use in claiming existing ...
0
votes
1answer
41 views

Bitcoin security/vulnerability on computer backed up by cloud?

I understand that BTC are stored as file in wallet.dat on hard/external drives. Is there an added layer of security to Bitcoin storage when the computer is backed up by a trusted cloud storage ...
-2
votes
1answer
139 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 ...
6
votes
1answer
110 views

Can I trust the peers I am connected to?

From my understanding of Bitcoin, it operates on a P2P network. Having just downloaded a wallet app, I see it is connected to 6 peers. Does the Bitcoin protocol rely on trusting these peers? What does ...
4
votes
4answers
195 views

How can one gauge the reliability, customer service, and transparency of bitcoin exchanges?

There are several exchanges for Bitcoin with a few highly respected ones like Mt.Gox, Bitstamp, bter, bit-e etc. I understand the reason why they require verification of users by supplying their bank ...
0
votes
1answer
120 views

Why are web based wallets not safe?

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?
1
vote
1answer
158 views

What's needed to host a competitive game site

Let's say I wanted to host a site in which users create their own accounts they deposit bitcoins in said accounts a commission of, say, 0.05% is kept of all the bitcoins that are deposited in the ...
1
vote
1answer
174 views

Is bitaddress.org compromised?

When I tried accessing https://www.bitaddress.org with Firefox, I was redirected to https://www.bitaddress.org/bitaddress.org-v2.7.2-SHA1-364542f1ccc5777c79aebb1692a6265cf3e42e7e.html and got a ...
1
vote
2answers
260 views

How secure is an encrypted wallet?

Would you store an encrypted wallet (backup) of significant value on dropbox? Assuming the passcode is good and secure. The wallet in question is bitcoin-qt, encrypted using the built-in encryption ...
3
votes
2answers
170 views

I'm mainly on a Windows system. What are some advantages and disadvantages of setting up Bitcoin-Qt in a Linux virtual machine?

I'm on Windows. Would it be a good idea to load up Bitcoin-Qt in a virtual machine running Ubuntu? What are some disadvantages I might run into? I was thinking it would be secure as everything is in ...
2
votes
1answer
128 views

How is network time enforced?

I've seen how nodes gather network time data, but how is it enforced in the blockchain? Are all of the timestamps digitally signed and included in the block as proof?
0
votes
2answers
249 views

Is the Trusted Third Party an advantage or disadvantage in regards to wallet security?

I'm new to bitcoin and have been reading some intros and FAQs. Most features of bitcoin seem better than our current currency systems. However, the one thing that strikes me is the ability to have ...