<blockquote>
  <p>Is there a specific attack or bug which asymmetric cryptography prevents during bitcoin transactions?</p>
</blockquote>

<p>asymmetric cryptography is not really something that was added on top of Bitcoin in order to prevent some specific attack or fix some specific bug.</p>

<p>asymmetric cryptography is one of two fundamental foundation stones, one of the two primary building blocks on which the Bitcoin concept is based. Without asymmetric cryptography and one-way hash-functions the whole idea of Bitcoin would not have got started at all.</p>

<p>asymmetric cryptography underlies almost everything that is important in Bitcoin. Without asymmetric cryptography there could be no Bitcoin.</p>

<p>If I had to identify one thing that asymmetric cryptography provides it is that it prevents 7 billion other people being able to remove money from <em>your</em> wallet whenever they want and you being powerless to stop them. Its the difference between putting your cash in a safe only you know the combination for and leaving your cash on a park bench in the center of a crowded city while you go elsewhere for a year.</p>

<p>You might enjoy watching the two videos at <a href="https://anders.com/blockchain/" rel="noreferrer">https://anders.com/blockchain/</a> (watch both and in the right order) They are very easy to follow and reasonably brief. The first sets the scene, the second builds on that to answer your question (but you have to watch the first before the second)</p>

CC BY-SA 4.0
2019-07-20T10:56:36.483Z
Can I share you my research work? so that i get my primary resource who can verify whether my informaiton correct or no. I am 17 and this is my school work. Help is needed
The Decoder
CC BY-SA 4.0
2019-07-20T19:40:45.633Z
More fundamentally (not specific to bitcoin/cryptocurrency), asymmetric crypto is what makes it possible to exercise any form of "control at a distance". Without it, there is no evidence to a person or machine carrying out your instructions that they're actually your instructions and not a misrepresentation by some party involved in conveying them.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2019-07-20T09:49:49.767Z
2019-07-20T09:55:20.200Z
2019-07-20T09:55:20.200Z
RedGrittyBrick
<p>Without asymetric cryptography, there wouldn't be information asymmetry: in other words, everyone knows exactly as much as everyone else. If everyone knows equally much, there is no way to distinguish a legitimate sender from a malicious one.</p>

<p>More specifically, if a symmetric construction like an HMAC was used to authenticate a transaction, miners would learn the key from legitimate spending transactions, and be able to instead mine an (indistinguishable and also legal) transaction that steals the coins.</p>

CC BY-SA 4.0
2019-07-20T08:37:22.193Z
2019-07-20T09:01:00.813Z
2019-07-20T09:01:00.813Z
Pieter Wuille
<p>Is there a specific attack or bug which asymmetric cryptography prevents during bitcoin transactions?</p>

<transactions><security><cryptography><attack>
To what extent does asymmetric cryptography secure bitcoin transactions?
The Decoder
# To what extent does asymmetric cryptography secure bitcoin transactions?

(Asked by: username_0 on 2019-07-20)

Is there a specific attack or bug which asymmetric cryptography prevents during bitcoin transactions?

**Tags:** transactions, security, cryptography, attack


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## 2 answers

### Answer by username_1 on 2019-07-20. Score: 6

> Is there a specific attack or bug which asymmetric cryptography prevents during bitcoin transactions?

asymmetric cryptography is not really something that was added on top of Bitcoin in order to prevent some specific attack or fix some specific bug.

asymmetric cryptography is one of two fundamental foundation stones, one of the two primary building blocks on which the Bitcoin concept is based. Without asymmetric cryptography and one-way hash-functions the whole idea of Bitcoin would not have got started at all.

asymmetric cryptography underlies almost everything that is important in Bitcoin. Without asymmetric cryptography there could be no Bitcoin.

If I had to identify one thing that asymmetric cryptography provides it is that it prevents 7 billion other people being able to remove money from *your* wallet whenever they want and you being powerless to stop them. Its the difference between putting your cash in a safe only you know the combination for and leaving your cash on a park bench in the center of a crowded city while you go elsewhere for a year.

You might enjoy watching the two videos at <https://anders.com/blockchain/> (watch both and in the right order) They are very easy to follow and reasonably brief. The first sets the scene, the second builds on that to answer your question (but you have to watch the first before the second)

> **Comments:**
> **username_0**: Can I share you my research work? so that i get my primary resource who can verify whether my informaiton correct or no. I am 17 and this is my school work. Help is needed  
> **username_2**: More fundamentally (not specific to bitcoin/cryptocurrency), asymmetric crypto is what makes it possible to exercise any form of "control at a distance". Without it, there is no evidence to a person or machine carrying out your instructions that they're actually your instructions and not a misrepresentation by some party involved in conveying them.  

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### Answer by username_3 on 2019-07-20. Score: 5

Without asymetric cryptography, there wouldn't be information asymmetry: in other words, everyone knows exactly as much as everyone else. If everyone knows equally much, there is no way to distinguish a legitimate sender from a malicious one.

More specifically, if a symmetric construction like an HMAC was used to authenticate a transaction, miners would learn the key from legitimate spending transactions, and be able to instead mine an (indistinguishable and also legal) transaction that steals the coins.


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