Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [public-key-infrastructure]

A public-key infrastructure (PKI) is a set of hardware, software, people, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates. In cryptography, a PKI is an arrangement that binds public keys with respective user identities by means of a certificate authority (CA). There are three main categories of PKI: Web / SSL certs, corporate networks, and Government ID / ePassport.

2
votes
1answer
48 views

How common is it for CAs to issue end entity certificates with Extended Key Usage marked as critical?

Does anyone know whether it is common for CAs to issue end entity certificates, which can be used as client certs (possibly among other purposes), with the Extended Key Usage (EKU) extension marked as ...
3
votes
1answer
148 views

What happens to PKI once quantum computers can break encryption?

They say that public key infrastructure or PKI uses very complex encryption. What if that encryption breaks one day when quantum computers complete? What if they decrypt all private messages and data? ...
2
votes
1answer
66 views

Certificates for autoscaling internal networks?

A public website with an SSL certificate makes use of a certificate and CA in order to establish trust between the server and client. How is the same thing typically implemented on private networks, ...
4
votes
1answer
31 views

Under what conditions is the Client trying “the next” CRL Distribution Point?

We've got a scenario where the CRL is distributed to 2 different Locations. One ist accessable from a private network and not from the internet. The other one is asseccable from the internet but not ...
0
votes
0answers
13 views

Force client or server to restart SSL handshake (or expire SSL session) [migrated]

I have a client (written in Java) which connects to an HTTPS server (the server written in Java also). The client certificate and trusted certificates are stored in a PKI token. The client sends some ...
2
votes
2answers
67 views

File integrity assurance

I have the following scenario : Two parties want to exchange files. First party publishes a file on a secure server First party sends to the second, a hash of the file in order to be able to verify ...
0
votes
0answers
24 views

Whether cipher suites is related to public key certificate? [duplicate]

I want to use TLS version 1.2 and Authenticated Encryption with Associated Data (AEAD). Can a public key certificate obtained from a certification authority specify which of the ciphers I can use? ...
1
vote
0answers
43 views

Get S/MIME from Digicert, store in escrow on on-prem CA

I'm trying to crack the following nut: I have a contract with Digicert for S/MIME certificates for my org. Digicert allows to use their API for cert issuance. Unfortunately I can't let users self-...
0
votes
1answer
38 views

RFC 5755 Attribute Certificate Validation

According to this explanation: Manually walking through the signature validation of a certificate I'd like to know how is the validation process of an RFC 5755 attribute certificates, because it ...
0
votes
1answer
31 views

truststore and intermediate certificates

We have a situation where our on premise product talks to a third party external API over SSL. This API has a certificate which is issued by an intermediate. We use the default java cacerts truststore,...
0
votes
1answer
48 views

Signing JWTs with server's SSL/TLS certificate

I have a server that needs to sign JWTs asymmetrically. I can either generate a new public/private keypair or re-use my keypair used for my server certificate. Is there any concern about re-using my ...
0
votes
1answer
38 views

Signing webhooks with asymmetric keys

I want to sign webhooks from my web service with a JSON Web Signature (part of JWT standard), ideally using asymmetric keys (so, using RSA or elliptic curve cryptography). What is the recommended or ...
1
vote
4answers
148 views

Do large companies use multiple public-private key pairs?

If I were to create a website I would then naturally generate a public-private key pair. The public key is published and the private key is kept private on the server. If the website has not a lot of ...
2
votes
2answers
128 views

Maximum number of certificates generated by a CA

What is the maximum number of certificates that can be generated from a CA? The use case is a VPN using certificate authentication and I would like to know what is the theoretical number of unique ...
0
votes
1answer
40 views

More clarity on Certificate, public key, hash

I'm new to this certificate and public keys. So I've a certificate. I exported as .pem. I opened it in textEdit and it looks like the below. I've used below command to see what this certificate ...
0
votes
2answers
38 views

How to approach 2 tier PKI RSA Root CA with subordinates that should support ECDSA

I have a situation for which I am not sure how to approach it. Basicialy I need to find out if it is possible how to issue ECDSA Certificates with a RSA Root Certificate. Is this possible? and how ...
0
votes
2answers
53 views

Is the root certificate issued from one Certificate Authority is same for all the requesting organisation?

Let me please explain the question a bit more through an example: There are lots of companies who have their certificates signed by Verisign (or any CA). I understand that Verisign signs these certs ...
0
votes
0answers
21 views

How related SSL/TLS to PKI? [duplicate]

It is not clear, how SSL/TLS related to PKI? It seems, PKI is part of SSL/TLS, but I'm not sure. Any clear explanation?
1
vote
1answer
36 views

Active Directory Certificate authentication trust

When setting up Smart card authentication you publish that Intermediate/Sub CA to the NTAuthCertificates object in Active Directory and certificates from that CA will now be OK for certificate ...
1
vote
1answer
67 views

Does the key size have an effect of the size of the public key and signature

If I have a 2048-bit RSA and a 4096-bit RSA key is my signature and public key smaller when I use a 2048-bit key vs a 4096-bit one ? (In bytes)
1
vote
1answer
68 views

Why can I use 2 different private keys to connect to my SSH server storing only 1 public key?

On my server ~/.ssh/authorized_keys contains only 1 public key. However, I can connect to it using 2 different private keys. One private key looks like this: -----BEGIN RSA PRIVATE KEY----- ...
2
votes
1answer
61 views

Standard practice for managing expired and revoked certificates used for signatures?

Curious to know what the standard practice is to maintain old/revoked certificates that were previously used to sign documents that must be verified in the future. For example, suppose there is a ...
1
vote
2answers
66 views

Can Asymmetric encryption be used instead of modern authentication strategy?

Assuming that I have a way to associate a combination of public private key encryption with real people/user. The private key is stored on the device of the user. User have to communicate with some ...
0
votes
0answers
45 views

X.509 Certitificate Authentication between Client / Server (REST Implementation Model)

Can you please list of advantages /disadvantages on X509 Certificate based authentication instead of traditional username/password model ? Architecture Scenario : Lets suppose i have Client ...
0
votes
2answers
44 views

Can certificate signing requests be stored at the server to prolong existing certificates?

I want to build a PKI (public key infrastructure) to host certificates for users. My use case is, that I want to use the certificates for e2e encryption between the users. Users must be able to ...
1
vote
1answer
96 views

One GPG key with multiple user identities for my career?

I am trying to work out what is the best approach for managing GPG keys over my career when I change jobs. My understanding is that there are two ways this could be done: Have one main/master GPG ...
8
votes
1answer
466 views

The difference between Subject Key Identifier and sha1Fingerprint in X509 Certificates

I have some SW that extracts certificates data and the SW utilizes OpenSSL. I am confused what is the difference between the subjectKeyIdentifier and the sha1Fingerprint. Both are hash values. My ...
4
votes
3answers
587 views

What is the best way to reissue user certificates after configuration change in a template?

I have setup my MS-ADCS environment in my company and configured auto-enrollment. i have everything working great, but found out that I want my "Subject Name Format" to have a different value. We are ...
4
votes
3answers
213 views

What if somebody sends me genuine certificate that they do not own? [closed]

I just started learning about the digital certificates, its architecture and how it works internally. What will happen if someone sends me a genuine certificate for authentication which does not ...
1
vote
1answer
147 views

Certificate serial and thumbprint number spacing

We have a Microsoft PKI setup at our organization. As per just about all certificates I've ever seen, new certificates issued by our issuing CAs will put the serial number and thumbprint in a HEX ...
0
votes
1answer
70 views

Mutual SSL for clients of SaaS cloud service

My company is launching cloud based SaaS service. There will be clients from different tenants connecting to our services via mutual SSL. The clients would use a library provided by us to connect to ...
3
votes
1answer
115 views

How can I use X.509 cross signing to replace a CA?

I have a self-signed CA that I want to rotate the key for. I want to use cross-signing to facilitate this, with gradual replacement of the certificate on the clients so they can still communicate. I'...
1
vote
0answers
47 views

Is there a compiled list of TEE (Trusted Execution Environment) manufacturer/CA certificates?

I may be misunderstanding TEEs (I just learned about them from an HN post), but I have question regarding the features that seem to allow what seems to be the perfect form of DRM (to my maybe limited ...
0
votes
1answer
93 views

How to get public key if we know domain name?

I am solving some CTF lab. I send a request and get response in which it contains cookie. Cookie has three element. First is token and something that is ecdsa signed. The second is domain name. The ...
1
vote
0answers
44 views

Identifying and understanding a cryptographic voting protocol

I am reading about a voting protocol using public key encryption. According to the notes, if A votes va, then A broadcasts Ra(Rb(Rc(Ea(Eb(Ec(va)))))). Here, Ra is a random encoding function which ...
1
vote
0answers
32 views

Malware abusing SSH agent active keys

I am thinking about this lately a lot, so I wanted to get someone else's opinion. Let's say that I have an SSH key agent (e.g. Pageant or ssh-agent) running in background with loaded keys (keys were, ...
0
votes
2answers
182 views

Rotating encryption keys - how does it work?

I haven't found a duplicate which explains with sufficient clarity how does the process of rotating encryption keys work in simple layman terms. I know how private/public key cryptography works, I ...
2
votes
1answer
84 views

How to Manage Public Key with Asymmetric Cryptography

I'm working on an iOS chat project using Firebase RealTime Database. I want to use asymmetric cryptography for the management of messages between two users .. Browsing the net I found an excellent ...
3
votes
2answers
104 views

Delivering data securely when the data source is the key maker

Let's say we have the following: Bob needs to send data securely to Alice. Only Bob and Alice are allowed to read/see that data. Alice is not able/allowed to create keys. Alice can use any number or ...
1
vote
1answer
53 views

Android hardware Keypair Info

Basically I would like to use Android Keystore to sign requests going to a server from an Android phone. My goal is to have a way of verifying the origin of the request. Does Android Keystore offer ...
1
vote
1answer
49 views

Public Key Crypto - sign Bob's name into Alice's message or encrypt Alice's name

I was reading Defective Sign & Encrypt in S/MIME,  PKCS#7, MOSS, PEM, PGP, and XML and in section 5.1  Naming Repairs By signing Bob's name into her message, Alice explicitly identifies him ...
1
vote
0answers
74 views

Why Diffie-Hellman instead of just share the secret [duplicate]

I read that D-H is used to make a shared secret between parties that then they use to encrypt the messages. This is used in TLS, for example, after the server has authenticated itself with a ...
0
votes
1answer
63 views

Verify the requesting domain

I have a both a http and websocket server written in nodejs (for now) and it will be receiving requests from many different domains. The request is made from the client using JS. I need to verify 100%...
1
vote
0answers
17 views

Root CA and Intermediate CA security [duplicate]

I'm confused how intermediate CA's adds to the security of the PKI. I realize the compromise of root CA key is catastrophic as it would've to be consequently purged from the trust store of every ...
1
vote
1answer
40 views

TLS Cipher Suites and PKI

I am currently trying to figure out what cryptographic algorithms are applicable when using mutual authentication for TLS with PKI-certificates. So when I am intitially creating a certificate, I ...
1
vote
2answers
63 views

Console based PKI auth (Xubuntu Linux)

Normally, I use my PKCS#11 card to logon to a secured site using a browser plugin which initiated a local software dialog to input PKI card PIN. Is it anyhow possible to do the following? Run some ...
1
vote
2answers
96 views

Why digital signatures needs different algorithm

Why digital signatures uses algorithms such as DSA, ECDSA or RSA-PSS, and not just the RSA algorithm to encrypt the message hash with the private key? Is the choice more security or performance ...
0
votes
1answer
34 views

Protecting Keys with External Factor

I have some symmetrical encryption keys (DEK) stored in the database alongside with the encrypted data. DEK's are encrypted by the public key of the HSM. The application server uses HSM with PKCS11 ...
3
votes
1answer
92 views

Concepts of PKI Encryption and Digital Signature Authentication [duplicate]

I am trying to understand how SSL uses PKI and Digital Signature authentication to ensure secure and verified communications. I've read various sources online and from what I can tell the basic ...
1
vote
2answers
71 views

What happens when the timestamper's certificate expires?

What happens when the timestampers certificate expires? If the code is now untrusted, can it be re-stamped without re-signing? If not, what good does this timestamp do me if my cert is valid until the ...