Bitcoin Stack Exchange
Bitcoin Stack Exchange

Questions tagged [cryptography]

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

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

285 questions
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What does the curve used in Bitcoin, secp256k1, look like?

I'm reading up on ECC curves and on many of them I see an illustration that looks like this What does the comparable curve in Bitcoin look like, or are all curves generally the same?
makerofthings7
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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 cryptographic strength?
Thilo
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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 cryptography pieces. Have any well-regarded cryptography…
lemonginger
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ECDSA: (v, r, s), what is v?

Deterministically signing a Tx with RFC6979 returns v, r, s, where r and s are the 2 values used in standard ECDSA signatures. v = 27 + (y % 2), so 27 + the parity of r, as pybitcointools indicates. So for even r, we get v = 27, odd r we get v =…
Wizard Of Ozzie
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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 rainbow tables utilize systems similar to those…
gesell
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What is the origin of insecure 64-bit nonces in signatures in the Bitcoin chain?

In Biased Nonce Sense: Lattice Attacks against Weak ECDSA Signatures in Cryptocurrencies Joachim Breitner and Nadia Heninger use a lattice based algorithm to recover private keys from signatures in the Bitcoin chain that were produced by insecure…
G. Maxwell
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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? For clarity's sake, a provably fair game is a…
ThePiachu
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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 systems? E.g. could an attacker input password…
John Nilsson
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What exactly is generator G in Bitcoin's elliptical curve algorithm?

What exactly is the generator G in elliptical curve math? It is typically described as a point on the curve. Is this a tuple of values? What properties does it have?
Eric S
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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. What mathematical property allows public keys to…
cdecker
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Problems with deterministic ECDSA based on RFC6979 in Bitcoin

Generating random number k in elliptic curve is crucial and in any transactions signature in Bitcoin, random number k is required to compute a point k*G. If this k is chosen not randomly, it instantly leaks the private key. Therefore, they came up…
abeikverdi
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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 bitcoin public keys in days rather than years.…
B T
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Byte array to hexadecimal and back again in JavaScript

I can generate a byte array with var myByteArray = window.crypto.getRandomValues(new Uint8Array(16)) and I get 181,143,16,173,231,56,63,149,181,185,224,124,84,230,123,36 I can then turn this into a string with…
Will-In-China
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How is the generator point G chosen in the secp256k1 curve used in Bitcoin?

The generator point G in the secp256k1 curve used in Bitcoin is a known constant: Gx = 0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798 Gy = 0x483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8 How was this point…
RocketNuts
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Is a bitcoin address collision possible if generating 90 million addresses every 4 hours?

I am running a test to see if I can obtain a successful bitcoin address collision after generating billions of addresses. I am not entirely sure how I would check them yet. Basically I have an extra 10TB hard drive and am running supervanitygen on…
Anonymous
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