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

learn more… | top users | synonyms

4
votes
1answer
98 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 ...
0
votes
1answer
53 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 ...
0
votes
0answers
7 views

Mining incentive and bitcoin limit [duplicate]

I am new to bitcoin, Sorry if this has been asked before. As I understand it mining provides the security for the blockchain in that it makes it hard to forge a transaction. The incentive for finding ...
1
vote
0answers
23 views

Is Bitcoin vulnerable to a Birthday Attack against Private Keys? [duplicate]

This is a definition of the Birthday Attack. Someone claims Bitcoin is vulnerable to such an attack in the bitcoin IRC chat. Are they correct?
0
votes
1answer
31 views

Faking transaction? [duplicate]

I have a question here. Lets says we have Nick, who has maybe 1 BTC on his account and Bob who has 0 BTC on his account. Can Nick transfer 10 BTC to Bob's account? I assume no. But what if he creates ...
2
votes
1answer
96 views

The shortest ECDSA signature

I want to create ECDSA signature {r,s} where r is very low (for example 1) and can be encoded in DER-format in one byte. How to calculate k value? Seems to me that it does not depend of anything. ...
1
vote
1answer
25 views

Duplicate r value for an address: only an issue for a multi-input Tx?

I've modified the r-scan Python code to look beyond the 50 Txs the Blockchain.info API usually returns. My modifications take all the r values for my address and look for duplicates, but a commented ...
4
votes
1answer
54 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 ...
2
votes
2answers
96 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 ...
-3
votes
1answer
48 views

In India how does one accept or give Bitcoin? Do we also get a physical coin for a Bitcoin? [closed]

I heard about Bitcoin and its endless possibilities to use Bitcoin irrespective of a particular geographic location. But my doubt is How does one accept and give a Bitcoin, Does it have its own market ...
0
votes
1answer
42 views

Reuse of addresses by a service (“get new address” returning *funded* addresses)

Recently, a marketplace was said to have been reusing deposit addresses, such that clicking the "get new address" button would immediately give the user a different address, however, the "new address" ...
2
votes
1answer
129 views

Who pays me when pool mining?

When I pool mine, do my payments come from the pool operator's personal account? From the pool's wallet? Or from somewhere else? When using P2Pool, the payments appear in bitcoin-qt as though I had ...
1
vote
0answers
23 views

Do any router custom firmwares enable Bitcoin for anonymous usage?

I want to find Wifi firmware where I can sell my internet service with anyone who needs to use it... ideally paying in an Altcoin or Bitcoin. Are there any router modifications that support a wallet ...
4
votes
2answers
157 views

How can services that use the bitcoin blockchain help secure it?

There are many projects being worked on that involve using the bitcoin blockchain for its public verifiability and immutability. A few examples would be Counterparty, Medici, Factom, etc. But each use ...
0
votes
2answers
62 views

Is an unencrypted wallet secure if bitcoind is not accepting RPC calls?

I'm interested in setting up a P2Pool node (which requires running bitcoind) to run a little mining pool for myself. Before you ask, nope I'm not even trying to break even, I know I'll lose money on ...
1
vote
1answer
265 views

As of Feb 2015, what's the most technically secure wallet for Android?

I want a wallet on my Android phone that is rooted. I'm new to bitcoins and I'd like to know which one is technically secure...if it helps, I'll be buying Canadian bitcoins.
0
votes
1answer
73 views

Pseudo-Node and putative attack vectors on the network

Pseudo-Node is discussed here on Reddit's /r/Bitcoin Essentially it functions to relay calls from connected nodes in a random fashion. This was an experiment into how easily can full nodes be ...
4
votes
2answers
105 views

Intercept and edit transaction output

When a P2PKH transaction is created there are two main parts: the transaction input and the transaction output. I understand that the transaction input requires a signature that unlocks a previous ...
2
votes
2answers
183 views

Can an attacker create many nodes that approve blocks without work?

There are currently about 7000 nodes in the Bitcoin network. The security rests on the fact that someone adding nodes would have have to expend CPU power to hash transactions. What prevents someone ...
2
votes
3answers
148 views

Can an exchange work which does not have control of the private keys?

It seems like there is really no great way to exchange USD for BTC. Having to trust an exchange with your private keys is undesirable. I'm wondering if there is a way to utilize the convenience of ...
5
votes
2answers
347 views

Proving a transaction is mine

As an assignment in a digital security course, a group of 100 students was asked to transfer a small amount in bitcoins to a certain wallet. They promised they'd buy something for us from this money. ...
5
votes
4answers
3k 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
votes
2answers
253 views

How could a time warp attack be prevented?

jarpian explains what a time warp attack (AKA zeitgeist attack) is: This is a 51% attack where the attacker sets the block timestamps artificially to lower the difficulty, allowing him to profit ...
0
votes
1answer
43 views

How can I be sure that bitcoin mining software is not compromised?

I have been interested of generating Bitcoins but how can I be sure that the software that is available for this is not somehow compromised? My concern is that the software may have some backdoor ...
1
vote
1answer
38 views

Confirmed transactions lost in my synchronised node

I tried to get a transaction information using RPC method getrawtransaction in my synchronized node, but I got no information about the transaction. I did it in another node, and I could get the ...
2
votes
1answer
114 views

How resilient are Proof of Stake (PoS) mechanisms to brute force quantum computing attacks?

The article called "Bitcoin vs. The NSA’s Quantum Computer" was a great read pertaining to Bitcoin, and computing minimum thermodynamic energy required to brute force attack public key to discover the ...
1
vote
2answers
130 views

How does Ripple ensure that transactions take place

I am struggling with some concepts in the Ripple system. As I understand it: After an American user goes to a gateway and loads $ into the Ripple system that he wants to send to Cambodia, the ...
1
vote
1answer
123 views

Encrypting Bitcoin private keys instead of printing out paper

I follow the procedure of making a cold storage wallet: downloaded copy of bitaddress.org using an off-line computer booted with Ubuntu from CD. Instead of printing out the private keys and ...
3
votes
1answer
120 views

Technical analysis of Blockchain.info security breach

I the news I read this: The firm was forced to make a security disclosure on its blog and on Reddit, admitting that a development error had led to a problem with the generation of private ...
1
vote
1answer
29 views

Funds and Wallets

If I load bitcoins to my wallet and the funds are there, and I go back to load more Bitcoins with a new address for my wallet are the funds from my first wallet going to merge with the newly added ...
1
vote
1answer
97 views

Lower confirmation time schemes: any requirement between confirmation time and the probability to find a block during that confirmation time?

Bitcoin, the first blockchain-based cryptocurrency, set a 10 minute confirmation interval time; LiteCoin set a 2 minute confirmation interval time; DogeCoin set it at 1 minute; QuarkCoin set it at 30 ...
1
vote
0answers
72 views

Which exchanges support U2F authentication?

I got myself a nice security key (Yubico Fido) today, which utilises the U2F protocol. But to my surprise not a single Bitcoin exchange seems to support this yet, only Google itself. So which ...
0
votes
1answer
122 views

Why are non-final transactions considered non-standard?

In IsStandardTx within main.cpp, there is a comment: // Treat non-final transactions as non-standard to prevent a specific type // of double-spend attack, as well as DoS attacks. (if the transaction ...
1
vote
3answers
233 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 ...
6
votes
1answer
218 views

Is there a fallback plan if bitcoin's underlying cryptography is cracked?

Lets say someone started making real viable quantum computers that were affordable enough that large companies could buy one. And lets say a quantum algorithm was devised to crack the private keys of ...
1
vote
2answers
286 views

Why don't any of the SHA-256 vulnerabilities matter for mining?

Wikipedia lists several vulnerabilities in SHA-256. Presumably, none of them can be used to mine faster, or it would be done already. Why don't these vulnerabilities lead to a problem for mining?
1
vote
2answers
56 views

Profit possibility for colluding with 51% attacker

The Bitcoin Wiki states "A profit-seeking person will always gain more by just following the rules, and even someone trying to destroy the system will probably find other attacks more attractive." ...
3
votes
1answer
82 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
230 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 ...
1
vote
2answers
264 views

How does a Trezor passphrase prevent restoration of a wallet if an attacker knows the seed?

Trezor User Manual says if you forget the passphrase there will be no way to recover your bitcoins. Not even the Recovery seed. How is it that you (or an attacker who knows the seed) can't just ...
2
votes
2answers
287 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 ...
3
votes
2answers
145 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?
2
votes
3answers
349 views

How can an online wallet be more secure than paper wallets or cold storages?

Recently, after I was reading that some bitcoin early adopter lost 750 BTC due to theft from his macbook, I was looking for the most secure storage solution for my coins. I already know about paper ...
0
votes
1answer
80 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 ...
0
votes
2answers
60 views

Hash property resistance

I'm experimenting with some self study cryptography and I was curious about the two following scenarios (simple answers and/or in relation to bitcoin) If SHA256 was found to lack pre-image ...
1
vote
2answers
132 views

Can you encrypt not just the private key, but also the public keys (ie bitcoin addresses) in an Armory wallet?

I would imagine that the paranoid darknety bitcoin user has an interest in keeping not only their private keys safe (so nobody can steal their bitcoins), but also has an interest in keeping their ...
1
vote
2answers
55 views

Theoretical security of mining bitcoins

Is it possible to change rules of mining bitcoin division? rewrite P2P bitcoin client (or write maleware) which will be pretending that fake bitcoin client is legal, original client distribute ...
0
votes
1answer
42 views

How do I reset my TFA token in Coinbase?

I would like to move my Coinbase Two-factor authentication token from one device to another. I cannot find a location on their website to disable TFA once it has been set up, or to move the token to ...
2
votes
1answer
75 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
91 views

Standardize wallet format [closed]

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 ...