Questions tagged [certificates]
A certificate consists of a public key and information about the owner (e. g. the name of a person or server).
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3answers
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X509 certificate
I am studying the X509 certificate structure and here is an OpenSSL configuration file for generating the certificate. ("sth" just mean the actual string is removed)
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2
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1answer
912 views
PKCS12 password of container and private key
As I understand pkcs12 defines a container structure that can hold both a certificate and one or more private keys.
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0answers
48 views
How do certificate authorities decide that a website is safe? [closed]
I have a rough idea of how SSL works, but how does a CA decide that a website is safe? Can't an unsafe online store easily get an SSL certificate?
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0answers
15 views
Do browsers know domains that are supposed to be encrypted? [migrated]
Do browsers have a list with sites that are supposed to be encrypted?
Could a man in the middle attack be performed by presenting a user a http site instead of an https site? That way the server would ...
0
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1answer
70 views
Difference Between PEM vs P12 vs CRT vs JKS vs keystore vs PKCS vs x509 certificates [duplicate]
Sorry noob here. I am so much confused about lot of files used client authentication certificates. Can anyone guide me on the difference between PEM vs P12 vs CRT vs JKS vs Keystore vs PKCS vs x509 ...
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0answers
38 views
Detecting revoked keys long after a document is signed
Scenario: A document is signed with a compromised private key, with a long-term time stamp. The normal expiration date of the key pair is D. The rightful owner of the key pair discovers the compromise ...
3
votes
1answer
88 views
Manually creating a GPG Public Key
I want to manually create a GPG public key that can be imported into GPG, i.e. I want to create a file with a Public-Key Packet, a User ID Packet and a Signature Packet (for an example see here). I ...
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0answers
19 views
Generate version 3 x509 certificate from version 1 CA
Please do forgive me for my naivety. I have inherited a legacy system wherein the CA which signs the certificate is of version 1. Is it possible to generate a x509 version 3 certificate which is ...
2
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1answer
293 views
Revoke a GPG key using previously generated revoke certificate after renewd (change expiration date)
I have few sub-questions
Do secret keys get expired, or just the public key gets expired?
Do I have to back up the master sec key each time I renew it?
For an ...
0
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1answer
44 views
What if the CSR is intercepted in transit while sending it to CA?
I was studying PKI the other day and I had a serious thinking about the following question.
What is CSR? - It is a block of encoded text that is given to the CA when applying for an SSL certificate ...
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0answers
18 views
Digital signature from hashing encrypted webpage
I'm studying for the Security+ exam with the help of Total Seminars' Udemy course and in one video they claim that a digital signature is generated by encrypting a message with the sender's private ...
4
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1answer
888 views
What information is signed by a Certification Authority?
What data does a CA sign?
I know that in a certificate there is plenty of information such a the serial number of the certificate itself, the X.509 version number, the user public key, the asymmetric ...
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0answers
62 views
is it possible to achieve authenticated key agreement without using PKI or pre-shared secret?
After reading different techniques to achieve authenticated key-agreement (X3DH, HMQV, Asynchronous Ratcheting tree, An efficient protocol for authenticated key agreement, I understood that all these ...
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1answer
47 views
OpenSSL - What Data Is Used To Create A Certificate's Digital Signature?
I am coming up-to-speed on OpenSSL certificates. In all of my research I see where "data" is hashed to create a hash value that is used as the basis for a certificate's digital signature. This hash ...
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1answer
62 views
How to compute certificates using Diffie-Hellman key exchange with certificates and Elgamal signature scheme
We consider the DiffieāHellman key exchange scheme with certificates. We have a system with the three users Alice, Bob and Charley. The DiffieāHellman algorithm uses p = 61 and Ī± = 18. The three ...
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0answers
9 views
Extract Certificates from Package File on Mac
I would like to manually verify the certificate chain on a package from my MacOS Catalina. I know that you can use the codesign --extract-certificates to extract certificates from applications, but I ...
1
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1answer
79 views
How message digest hash is used in RSA digital certificate verification
This is how I understand digital signature verification to work in general:
Plaintext gets run through a hashing mechanism to make a message digest (IBM's terminology, there appear to be plenty of ...
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0answers
67 views
Include TSA Certificate in Timestamp Request
I'm currently working on Timestamping and stumbled upon a parameter fRequestCerts/requestSignerCertificates/certReq that according to the documentation (1, 2) tells a TSA to include the certificate ...
5
votes
4answers
8k views
Diffie-Hellman Key Exchange with Authentication: Man-in-the-Middle query
I have been reading up on MiTM attacks, and the prevention of them using public key certificates. Recently I learnt about Diffie-Hellman Key Exchange with Authentication, and how it uses signed ...
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0answers
44 views
Review: peer-to-peer encrypted communication
I'd like to ask you to review security of the following communication scheme:
network is strictly P2P, based on DHT (peer discovery)
root user can create a virtual private network (network private ...
1
vote
1answer
23 views
Is a Qualified Digital Certificate backward compatible with existing certificate code?
I'm trying to determine if our digital signature generation code will work without change using a European Qualified Digital Certificate in place of the RSA signing certificate that we normally use.
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0answers
20 views
Sorted merkle tree versus rsa accumulator
When compared to sorted merkle tree and rsa accumulator, which one is the best? Rsa accumulator has constant proof and it adds/deletes at constant cost. What is the verification cost for rsa ...
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0answers
16 views
Rsa accumulator verification cost gor nonmembership testing
What is the verification cost of rsa accumulator gor non-membership testing. Is it O(N) or O(1). Can somebody explain it to me?
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0answers
15 views
Merkle tree verification cost calculation
I am trying to understand how to calculate verification cost of sorted merkle tree in case of exclusion proof. For example 5 revoked certificate are kept in merkle tree. How can i calculate storage ...
2
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0answers
30 views
Rsa accumulator storage size
Rsa accumulator's storage complexity is known as O(1). However, how can i calculate size of accumulator value in byte?
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0answers
34 views
certificate revocation list file size
Crl files are growing linearly. I wonder with 10 revoked certificate, what is the storage size of crl file and so on. For every revoke certificate, how much increase the size of the crl?
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1answer
33 views
X.509 ECDSA signature field in DER format includes '00' between bit string and sequence of r and s
I created a X.509 certificate with ECDSAwithSHA256(OID=1.2.840.10045.4.3.2) by openssl.
ECC parameter is secp256r1.
Following is the signatureAlgorithm and signatureValue.
...
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0answers
25 views
Implementing ESignature and digital certificate
I'm having some issue understanding the mechanism of electronic signature and how implementing it
Here what I understood, correct me if I'm wrong:
(Client is here an android or ios device. Server ...
2
votes
1answer
43 views
Enforce weak RSA in TLS
I'm going to give a small talk on the mathematical background of RSA. My audience will consist mostly of software engineers and to make the mathematical stuff tangible, I wanted to demonstrate how to ...
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0answers
29 views
Keeping a backup of asymmetric keys with the help of a certificate authority without losing the privacy
First I'll explain the problem, then I will also give a solution(it might be wrong) I've found for it, you let me know what you think about this solution and whether you have a better one.
Assume a ...
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1answer
523 views
How is Cross-Certification implemented?
I am currently learning about Certificates in Public Key Infrastructure.
Cross-Certification exists as an alternative because the concept of a single monolithic CA certifying every possible user in ...
0
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1answer
45 views
How is a digital certificate generated?
I understand that the role of a Certificate Authority is to SIGN (not encrypt) a certificate. The signed certificate will theoretically contain:
Plain text of data, including the server's public key
...
74
votes
12answers
15k views
Who verifies the trust of certificate authorities?
Background
I am a novice in the field of cryptography and cyber-security, and while studying asymmetric-key encryption, I learned about the potential of a man-in-the-middle attack.
To mitigate this ...
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0answers
27 views
Will CT (Certificate Transparency) override the use of CAA and/or DANE/TLSA records?
I'd want to know if some of these competing technologies has more chance to survive. It seems they are thought to solve a similar problem by different manners and I'd want to stick to the most ...
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1answer
52 views
Is this pairing scheme for establishing trust between two devices with self-signed TLS certs secure from MITM?
Assume two devices (A and B) with self-signed TLS certificates (this part can't change). We want these devices to trust each other.
One way to do this is to simply copy A's cert over to B's allowed ...
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2answers
3k views
Where is Signaturevalue in Certificate?
Where is the Digital Signature value in my certificate? I can find Signature
Algorithm and Signature Hash algorithm.
Also why there are two fields specifying the Signature's Hash? With Signature ...
-1
votes
1answer
66 views
I am new to digital certificate 509V3 concept. can some one please clarify the below points [closed]
I am using RSA 2048 with SHA 256 primitive in certificate:
How to verify the user certificate n + 1 with Root certificate n?
why it is required to perform Certificate chain verification?
How to ...
4
votes
1answer
149 views
What security do digital signatures provide (like used when signing PDFs)?
I want to ask you one question about digital signatures as they are (for example) used when digitally signing PDFs.
We know that if our document has a digital signature, we can detect if the original ...
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1answer
114 views
Signature Verification: High level
I'm trying to understand how certificate signing and verification works conceptually. I know the classic example with asymmetric cryptography- the sender encrypts data with public key of receiver, ...
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0answers
61 views
How does DHE-RSA work and why is PFS guaranteed?
How does it work and why is forward secrecy guaranteed? I understood that it is not susceptible to a man-in-the-middle attack by using certificates in the beginning.
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1answer
114 views
Create self signed certificate from modulus, private and public exponents of RSA
I have the values of RSA public exponent $e$, the secret exponent $d$ and the modulus $n$.
How can I create (for example using openssl) a self-signed certificate using the RSA key $(n,d), (n,e)$? Is ...
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0answers
93 views
How to validate the authenticity and integrity of an XML document?
I am working on a C++ desktop application that reads an XML (also created by my org) from a public server (does not require authentication). I would like to make sure that the downloaded XML has not ...
0
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1answer
67 views
Observing cipher suites and certificate algorithms without man-in-the-middle
I manage a proxy server. Is it technically possible to observe and determine which cipher suite is selected between end points (client and server) without changing their SSL certificate, without ...
3
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0answers
69 views
Do people sign my subkey?
So, I've generated my GPG key pair. Created a subkey for signing and a subkey for encryption. Exported the whole thing, removed my master key pair to a secure place, re-imported only the subkeys. Now, ...
Squeamish Ossifrage
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1answer
139 views
How are all necessary parameters shared between signer and verifier in the ED25519 signature scheme?
I want to use the ED25519 signature scheme in my application which requires frequent sharing of secret data between two entities in the public domain.
I know that the Schnorr signature scheme has a ...
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1answer
91 views
Why do we need HMAC?
AFAIK, HMAC solves the collision problem of hash algorithms by mixing in a pre shared secret.
Can't we just use the pre shared secret to symmetrically encrypt data and leave out the hashing?
2
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1answer
986 views
How android apk file signing works?
There are a number of pages on web to tell how to sign apk file for Android. But none I've found telling how it works under-the-...
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0answers
39 views
what is the difference between self issued and an intermediate certificate
Hashicorp vault has an API they call Sign Self-Issued. The use case is for rotating root CAs. A user creates a new root self signed CA and then passes it to this API and what is returned is roughly ...
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1answer
150 views
What does (06) in “CRL Signing (06)” mean?
In "Certificate details -> key usage -> CRL Signing (06)", what does "(06)" in "CRL Signing (06)" mean?
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2answers
127 views
How are CRL implemented?
The source from where I learn states:-
CRL (Certificate Revocation List) is the primary means of checking status of certificates offline.
But I can't seem to understand how is it possible for a ...
