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Topic: Asymmetric encryption(signature)--DSA(A novice explanation) (Read 270 times)

member
Activity: 98
Merit: 173
Pooya87 sometimes seems to me that you are too kind to people around you, including newbies ... I just want to say that I just feel sorry for your time spent on answering this guy, since being guided only by logic, we can confidently say that he did not understand anything from what he published and, as a result, did not understand anything from your explanations.

Thank you very much for pointing out my mistake and thank Pooya87 for explaining it to me.

I now take pooya87's advice , don't try to explain what u are not familiar with.

The sentence that was judged to be plagiarized. It is about the history of DSA, so I directly move that sentence here. My knowledge of history can only be obtained from books.

Thank you for pointing out my mistake, I will correct it.And I changed part of the content.

I put a link to the article you found and some explanations about this thing at the beginning of the post.
legendary
Activity: 1456
Merit: 5874
light_warrior ... 🕯️
It is not your English, there are fundamental flaws in what you explain. Maybe you should avoid trying to explain to others things you don't fully understand yourself.
Pooya87 sometimes seems to me that you are too kind to people around you, including newbies ... I just want to say that I just feel sorry for your time spent on answering this guy, since being guided only by logic, we can confidently say that he did not understand anything from what he published and, as a result, did not understand anything from your explanations.

  • Source:

In August 1991, NIST (Nation Institute of Standards and Technology) proposed the Digital Signature Algorithm (DSA) for their Digital Signature Standard (DSS).

DSA is an algorithm and DSS is a standard. The standard uses algorithms, and the algorithm is part of the standard.

But the NIST announcement has caused a lot of condemnation, and these condemnations are more political than academic. Many large software companies that have obtained patent licenses for the RSA algorithm have also stood up against DSS. They have invested a lot of money to implement the RSA algorithm, and they certainly don't want these funds to be lost.
member
Activity: 98
Merit: 173
No it is not.
Private key is used in a mathematical equation to create the signature using the message hash.
The private key is encrypted to generate a digital signature →Private key is used in a mathematical equation to create the signature using the message hash.
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Not exactly correct.
Checksum (hash) is used for integrity check (ie. make sure data was not modified during transmission) DSA is used for authenticity check (ie. make sure the intact data that was downloaded is coming from the source we expect it came from) this process covers integrity check too.
This verification process can be divided into checking completion and checking authenticity
Quote
Wrong. DSA is used mainly for authentication not encryption.
Yes, you are right.
Quote
It is not your English, there are fundamental flaws in what you explain. Maybe you should avoid trying to explain to others things you don't fully understand yourself.
This is not a teaching/tutorial post. I recently studied the content of DSA and wanted to get criticism and guidance from other people on the forum, so I posted it in Beginners & Help. Before I learned enough, I didn’t dare to post in a similar section of Development & Technical Discussion.

Finally, thank you for your guidance. You are really knowledgeable and I am very happy to get your reply.
legendary
Activity: 3472
Merit: 10611
The private key is encrypted to generate a digital signature,
No it is not.
Private key is used in a mathematical equation to create the signature using the message hash.

Quote
The function of digital signature is to verify that data is not modified during transmission.
Not exactly correct.
Checksum (hash) is used for integrity check (ie. make sure data was not modified during transmission) DSA is used for authenticity check (ie. make sure the intact data that was downloaded is coming from the source we expect it came from) this process covers integrity check too.

Quote
Digital signature is an upgrade of one-way encryption.
Wrong. DSA is used mainly for authentication not encryption.

Quote
  • Mathematical logic
The quote here seems out of context. I also didn't get what certain parts are like "q" that is said to be 160 bits!

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I am not a native English speaker.
It is not your English, there are fundamental flaws in what you explain. Maybe you should avoid trying to explain to others things you don't fully understand yourself.
member
Activity: 98
Merit: 173
My explanation of this post,about being questioned as plagiarism
  • Introduction
https://www.programmersought.com/article/7824960278
Thanks to ICopress for pointing out this link. This sentence is about the history of DSA.archive
Quote
In August 1991, NIST (Nation Institute of Standards and Technology) proposed a digital signature algorithm (DSA) for use in their digital signature standard (DSS)
Code:
DSA is an algorithm, and DSS is a standard. The standard uses algorithms, algorithms are part of the standard.
    But NIST’s announcement has caused a lot of condemnation, and these condemnations are more political than academic. Many large software companies that have obtained the RSA algorithm patent license have also against DSS. They have invested a lot of money to implement the RSA algorithm. Of course, they do not want these funds to be lost in vain.

    This is a more advanced method of verification, not only public key, private key, but also digital signature. The private key is encrypted to generate a digital signature, and the public key verifies the data and signature. If the data and the signature do not match, the verification fails. The function of digital signature is to verify that data is not modified during transmission. Digital signature is an upgrade of one-way encryption.
  • Mathematical logic
Quote
(1).The public key y consists of 4 parameters
y :y= gx mod p
p:512~1024 bit prime number
q:160 bits and a factor that is relatively prime to p-1
g:g=h(p-1)/q mod p, where h is less than p-1,h(p-1)/q mod p> 1
The public key is (p, q, g, y)

(2).Private key x in DSA signature:
x:x
(3).Message digest h(m)

(4).The signature process in the DSA signature algorithm:
r:r (signature) = (gk mod p) mod q
s:s(signature) = (k-1 (H(m)+xr )) mod q
The signature is (m, r, s)

(5).The verification process in the DSA signature algorithm:
Verification: (m2, r2, s2)=(m, r, s)
v = (( gu1 × yu2 ) mod p ) mod q
w = s-1 mod q
u1 = (H(m)×w)mod q
u2 = ( r w ) mod q

If v=r, the signature is verified
  • process



I am not a native English speaker. If I have logic errors, grammar and vocabulary errors, please help me to correct them. Thank you.[/list]
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