Questions tagged [certificates]
A certificate consists of a public key and information about the owner (e. g. the name of a person or server).
284 questions
7 votes
4 answers
2k views
Can Alice deny her signature by retracting her public key?
Alice sends Bob an arbitrary message M, signed with her private key. Bob verifies M with her public key A. Later, Alice claims that her public key was actually B all along, and M cannot be her message....
- 173
2 votes
3 answers
440 views
Finding the public key of the domain owner in domain name certificates
As you know, browsers provide www. domain name certificates which involves: Subjects name Issuers name Public key info ... ... and so forth with different type of signature format. Is there a domain ...
- 23
1 vote
1 answer
173 views
What is the current state of PQ certificates and industry choices ? What about Microsoft?
It is painful to find clear info on the web about PQ certificates, so I open this thread. I have some questions about PQ certificates. For "pre quantum" crypto, most of the companies use X....
2 votes
0 answers
47 views
HSM clarification
I need to buy an HSM for a project (need it for compliance with government regulations) and I am kind of confused. Price range is really wide. I can see used THALES nCipher HSMs on eBay for as low as ...
- 121
0 votes
0 answers
209 views
Self-signed certificate for S/MIME signature
I'm trying to programatically send an email with an S/MIME signature using a self-signed certificate, but Thunderbird keeps showing an error on the signature. Digital signature is not valid This ...
- 101
0 votes
0 answers
101 views
SSL certificate fingerprint mismatch between OPNsense and browser
I've configured an OPNsense firewall's web GUI to use a self-signed certificate with the following SHA-256 fingerprint However, when I open the web GUI from a web browser, it is showing a different ...
- 101
2 votes
1 answer
297 views
Correct my understanding of Digital Signature Algorithm for TLS certificates?
I just read the Wikipedia page on the Digital Signature Algorithm here: https://en.wikipedia.org/wiki/Digital_Signature_Algorithm Is the signing algorithm explained on the page the one that is used by ...
- 137
2 votes
1 answer
120 views
Signature Chains: Ensuring Authenticity and Trust
I'm studying for an exam and came across this question: When an electronic signature of a message claimed to be produced by Alice is verified we typically verify (at least the first time): that the ...
- 35
1 vote
0 answers
133 views
X509 Name Constraints in a 3-tier PKI - setting at the intermediate CA?
I have been playing around with implementing a three-tier PKI recently. My PKI structure is as follows: Root CA Intermediate CA 1 (Name constraint: DNS .example.com, Email: .example.com, pathlen 1) ...
- 163
1 vote
1 answer
66 views
Use of CertificateVerify in TLS_DH_RSA with client authentication?
Does anyone know if CertificateVerify is sent in TLS_DH_RSA with client authentication? Does anyone know the RFC or could explain the meaning of it? With TLS_RSA, a ...
- 21
1 vote
0 answers
365 views
TLS 1.3 key_share capture without certificate exchange
I am working on an investigation on TLS 1.3. I've came across an article of qacafe where they shared a TLS 1.3 handshake sequence. Wireshark capture. In this capture you see that in the Client Hello a ...
1 vote
1 answer
349 views
X.509 CA bundle content
I recently looked into the subject of public key cryptography (especially with X.509 certificates). I am the administrator of a web server using HTTPS which uses 2 levels of certificates (in addition ...
user110148
1 vote
0 answers
98 views
Error to create PQ certificate in C - x509 certificate routines:X509_PUBKEY_set:unsupported algorithm
I'm learning OQS OpenSSL and I'd like to create a certificate with dilithium in C, using liboqs and OQS OpenSSL. This is my code (based on https://stackoverflow.com/questions/256405/programmatically-...
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1 vote
1 answer
85 views
How to authenticate multiple IOT devices having unique certificates (ECDSA)?
I'm relatively new to the field of security. I'm working on an IoT system with WiFi-connected nodes (Bio-sensing devices) communicating with a server for centralized monitoring. I need to authenticate ...
- 13
1 vote
3 answers
393 views
How do certificates add data to public key and how is this implemented into TLS?
I want to create a self signed PKI for a couple servers I am running. I am finding tutorials with copy paste commands from openssl, and hand waving explanations that describe the general purpose of ...
- 11