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Questions tagged [cryptography]

Concerning the broad subject of cryptography and its narrow application in Bitcoin protocol and applications.

3
votes
1answer
580 views

The compressed public key byte header

I've noticed that compressed public keys are always either 0x02 or 0x03, but what exactly determines whether it's 0x02 or 0x03? I can go look at the OpenSSL code to answer this, but I'm hoping someone ...
6
votes
1answer
605 views

Recovering the last few digits of a Litecoin private key

Is it possible to recover the last few lost digits (10) of my Litecoin wallet private key? Are there any recovery tools available? Or will I have to try and roll my own? Crucially, what crypto ...
2
votes
2answers
2k views

Economics of Bitcoin Mining [duplicate]

I thought I understood the gist of what "bitcoins" are: electronic currency tokens representing $X USD that could be used to trade, buy or sell online items. But recently I heard the term "mining for ...
5
votes
1answer
1k views

Address Public Private key verification [duplicate]

Apologies if this question has been asked before, but when a bitcoin client wishes to send funds to an address, does the bitcoin protocol force the client to verify that the address has a ...
6
votes
1answer
256 views

What standard is used for the ECDSA to verify transactions?

Bitcoin used Elliptic Curve Digital Signature Algorithm. (see here). I'm wondering what standard is actually used for this Algorithm: which curve? which prime? Can anybody give me a reference? (Wiki ...
2
votes
2answers
218 views

When will the public key of an address used in the network?

On block explorer there are some address with public key available, and some without. (e.g. this one has public key: http://blockexplorer.com/address/1HBheYzvX7NDtcwVrMS7gxReNRVezYS7w2 , and this ...
12
votes
3answers
1k views

Can the Bitcoin network be used for cracking?

I'm assuming that the Bitcoin economy is rapidly building a computing cluster capable of unprecedented amount of hash searching. Would it be possible for an attacker to leverage this to crack other ...
2
votes
1answer
4k views

How does bitcoin work from a technical computer science cryptography perspective?

How does the cryptography science behind bitcoins work to make it robust(reliable , scalable). I am interested in technical explanation with cryptography math and not just conceptual explanation.
3
votes
0answers
66 views

Can there be Bitcoin-like network that also works as whatever@home? [duplicate]

There are Bitcoin-like network that performs calculations that are not locally useful, but interesting for peers. There are {SETI,folding,...}@home networks that calculates something that is (...
7
votes
2answers
2k views

If SHA256 and/or RIPEMD-160 were broken, would all bitcoin addresses be compromised?

If not, what else would be needed to steal all funds from all people and completely break bitcoin? I bet some will say ECSDA gives bitcoin an additional layer of protection. I counter this by saying ...
0
votes
1answer
1k views

Could mining calculations be used to crack private key? [duplicate]

Could mining calculations be used to crack private key, in addition to mining for checking against few million accounts with positive balances? If that possible, at the current mining rate (30TH/s) ...
2
votes
1answer
325 views

How can I use message signing to prove that I have private keys for many different accounts?

I want to prove the total sum of BTC I have access to. Therefore I think if I use message signing to assert "owned by makerofthings7" in each address, then anyone can compute the total coins in my ...
33
votes
5answers
11k views

Bitcoin Mining ASICs used for cryptographic application? Rainbow tables?

What is the potential that the ASICs being developed for mining could be used for other cryptographic applications such as building rainbow tables? I know that for instance those that crack GSM with ...
5
votes
1answer
311 views

Does a Vanity Address reduce the randomness / entropy of the private key? Is there cryptographic proof?

Since a vanity address discards many "valid" keys in order to find one that matches a pre-determined string, I think that the "randomness" of the data would be reduced, thus weakening the key. Is ...
7
votes
1answer
541 views

What OpenCL video cards (or FPGAs) are best for multiplication?

I'm benchmarking some Bitcoin related software and am looking for cards that are better at parallel multiplication vs parallel addition. Is there any prior work that may have this information? ...
1
vote
2answers
586 views

Do vanity addresses lower the security of my key? (reduced complexity)

Do vanity addresses somehow decrease the security of my private key?
11
votes
1answer
598 views

What mathematical property links the Armory chain to the public/private keys?

According to the Armory site the Public Keys needed for the Bitcoin addresses can be generated without having access to the Private Keys, which ideally are stored on a completely different computer. ...
15
votes
6answers
3k views

Which Bitcoin-powered gambling sites are “provably fair”?

Through the spread of Bitcoin for the purposes of online gambling, the concept of "provably fair" games came more into the limelight. Which of the Bitcoin-powered gambling websites are provably fair? ...
6
votes
1answer
1k views

Where and how is secp256k1 used within Bitcoin?

Bitcoin is unique that is uses secp256k1 to secure it's transactions; and any cryptographic attack against this algorithm is probably going to be percieved as an attack against the bitcoin network. ...
6
votes
1answer
433 views

Bitcoin Research

I have recently been assigned to advise a student on a senior thesis in math. She has taken linear algebra, introductory real analysis, basic cryptography, and abstract algebra. Her interest is in ...
0
votes
0answers
69 views

How secure is a private key? [duplicate]

Possible Duplicate: Is it possible to brute force bitcoin address creation in order to steal money? I've tried brainwallet.org and now I wonder, what happens if someone starts to generate a lot ...
61
votes
4answers
21k views

What is a compressed Bitcoin key?

The standard Bitcoin client in version 0.6 apparently introduces compressed keys. What are they? Are there any drawbacks to using them? Any incompatibilities with older software? Reductions in ...
-1
votes
1answer
406 views

How does a signed public key look different from an unsigned one? [closed]

I read this: "Public-key cryptography uses key pairs, a public and a private one, that can be generated by a user at any time. As the name implies, the public key gets distributed, while the private ...
3
votes
1answer
508 views

How do we have one-to-one mapping given the key size differences?

If public keys are 34 characters long, and private keys are 61 characters long, then the combinations of 34 characters is not sufficient to give each combination of 61 characters a unique pair. My ...
6
votes
4answers
857 views

Is it possible to forward bitcoins without the private keys?

According to this question, there isn't an easy way to automatically send bitcoins from one address to another and I think that it might be useful. So I thought about creating a website were people ...
54
votes
4answers
6k views

Have any cryptography experts vetted the bitcoin source code?

Theoretically, bitcoin's open source nature makes it more resistant to bugs and exploits. However, due to the specialized nature of the code, even many programmers don't fully understand the ...