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 ...

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58
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3answers
5k views

Why aren't IMSI catchers rendered ineffective by standard MITM defenses?

There's been a lot of reporting in the past few years about law enforcement agencies using IMSI catchers (also known as Stingrays after a popular brand of them) to intercept cellular communications. ...
3
votes
1answer
82 views

How can I enforce that an SSH private key has a passphrase?

My company is serious about security and willing to move to SSH key-pairs. Users can generate their SSH key pairs independently and I worry if they set a pass-phrase. Can I enforce this? Does signing ...
3
votes
2answers
140 views

Can a CN-only certificate bypass a name constraint if the CA goes rogue?

I am trying to cross-certify an internal issuer certificate, adding a name constraint for our domain. However, it seems that an attacker could bypass this protection by putting the desired host name ...
0
votes
2answers
124 views

How In-House Certificate Authority works (e.g. EJBCA)

I have a simple (dumb?) question with respect to EJBCA. I have been exploring how In-house CAs work and issue certificates. However, I am not able to understand who will be trusted on the top level in ...
5
votes
2answers
155 views

Why is weakness of SHA-1 considered a threat to TLS security

If I understand correctly the role that a hashing algorithm (e.g. SHA-1) plays in TLS certificates is as follows: The hashing function is applied to a subject's public key. The CA then uses their ...
1
vote
1answer
80 views

ECDSA implicit certificate using OpenSSL

I am trying to generate implicit ECDSA certificate only for signing and verification using OpenSSL. I tried google but I am getting many research papers. I understood that A messages need to be signed ...
1
vote
2answers
51 views

Client verification with PKCS#7

When a client sends you a pkcs#7 file to communicate with you, Is this because the file has their public key(certificate) and their chain and to avoid the confusion on your side what needs to be there ...
0
votes
1answer
117 views

CSR with only public key with openssl

So I have been doing my research and haven't found anything specific enough to my problem. As the question title states, I want to make a CSR with only the public key. What I have been able to do is ...
3
votes
1answer
146 views

Understanding how does certificate validation work

I'm using Wireshark for better understanding how is a SSL connection established. I captured the traffic of visiting three pages: reddit, facebook and this one. All HTTPS of course. Reddit: after the ...
2
votes
0answers
27 views

Finding the EMSA-PKCS1-v1_5 DigestAlgorithm field in the x509 certificate

From the RFC - https://www.ietf.org/rfc/rfc3447.txt A.2.4 RSASSA-PKCS1-v1_5 For each OID, the parameters field associated with this OID in a value of type AlgorithmIdentifier shall have a value ...
0
votes
1answer
50 views

Two issuing CAs in a two-tier PKI (Windows Server 2012)

I'm planning to setup two-tier PKI in my environment. We have two remote sites connected via a VPN. I think it is OK to set up both Root CA and Issuing CA on the 1st site. But, for example, I have ...
1
vote
1answer
95 views

Can Passpoint X.509 certificates be used to MITM SSL connections on Passpoint networks?

Passpoint/Hotspot 2.0 public networks like LinkNYC require users to install X.509 certificates, for EAP authentication. Can these certificates be used by the provider to execute man-in-the middle ...
0
votes
0answers
40 views

Storing Keys on Embedded Devices

What is a reasonable way of storing private keys/certs on an embedded device that doesn't have trust-zone, TPM or write-once storage? Without hardware backing the key-storage the key must be stored in ...
0
votes
1answer
24 views

SSL key exchange [duplicate]

As I understand, when I log on to a website via HTTPS, the public keys are shared in the beginning of the conversation. I have read around the internet is that if a MITM manages to read the entire ...
-5
votes
1answer
91 views

Mobile number tracking

Is there any way we can track our mobile when it is lost? I have done a google search on the same and found that we have websites which give us the details of where the SIM was purchased & ...
2
votes
1answer
81 views

How do “certificates” hold “keys”? [duplicate]

I am new to the realm of security and keep hearing about "certificates" containing "keys". But no one has been able to actually explain to me what is actually meant by this. I assume that the ...
0
votes
1answer
33 views

What's the actual danger of public key spoofing?

I am reading an excellent beginner's cryptography tutorial, and on this page there is the following blurb: Public-key cryptosystems have one significant challenge − the user needs to trust that ...
0
votes
0answers
51 views

Digitally signing a digital signature

When might it make sense to digitally sign a digital signature?
0
votes
0answers
53 views

DSS digital signing approach

Under the DSS approach to digital signing, what is the advantage of using two pairs of keys for each signature?
4
votes
1answer
100 views

Should my company change the internal Root CA hash method from SHA-1 to SHA-2?

My company have a Root Certificate Authority which is installed on a Windows Server 2003 and uses SHA-1 as hash method. We will migrate to Windows Server 2012. Checking the root certificates of my ...
0
votes
3answers
139 views

Difficulty of breaking private key password

I was recently reading up on the practices of keybase.io and came across this blog post. In it, the author says: ...decrypting the above [encrypted private key] is arguably as difficult as ...
1
vote
1answer
57 views

Why is it not recommend to use permanent validity of certificate for public key [duplicate]

As we know it is not recommended to provide permanent validity of certificate for public key. I don't know why. Could you give me some reasons ?
1
vote
2answers
115 views

sharing private key sTunnel

All of the sTunnel guides and implementations at work do the same thing, they say once the private key and the public cert are created on the server, you need to cat them together and then share with ...
-5
votes
1answer
83 views

What happens if two parties have the same public key? [closed]

What would happen if I get a public key that someone else already has? Isn't the security very weak in that case?
0
votes
1answer
192 views

BLS signature java implementation needed (if possible, along with some example code)

I need to sign a string with the shortest digest possible using regular certificate like X.509. As far as I understand, I will have to transform the string to the sequence of bytes, then sign. After ...
0
votes
2answers
44 views

How to avoid writing .pem while signing a csr?

I am using following command to sign a certificate, openssl ca \ -in client.csr \ -keyfile server.key \ -cert server.crt \ -outdir ./some_dir \ ...
2
votes
2answers
133 views

Self-signed cert - how it works

I am new to SSL / digital certificates / signatures. What I know is that a digital signature must be verified/decrypted using the public key. So a cert that is signed by a CA must be verified/...
0
votes
1answer
48 views

Authenticating a user by verifying a signature

Background I'm setting up an API which will be used primarily over HTTPS (only calls not needing any security what so ever is available over HTTP). Some aspects of it need to be accessed only by ...
3
votes
2answers
60 views

Comparing allegedly identical OpenPGP keys published through different channels

tldr version: When I try to compare public keys that are supposed to be for the same entity the versions I get through different channels are NOT the same and the ones that I download as a file like ...
4
votes
1answer
49 views

Can I get SSL certificates for my OpenPGP key?

How can I use letsencrypt to get a signed public key for use with OpenPGP? So I can prove in court the key is mine etc., and not have to rely on the OpenPGP web of trust.
0
votes
2answers
130 views

SSL digital certificate process - high level

I am a project manager and is touching on an IT project consisting of the usual 3 tier - web/client - middleware - database. In this case, I have an web server and needs to implement SSL ...
4
votes
1answer
101 views

SSL/TLS: Policy Constraints vs. Basic Constraints

Could someone please explain the difference between Policy Constraints and Basic Constraints? It appears to me that they are either redundant, or two names for the same thing. I would love some ...
9
votes
1answer
111 views

What LDAP schema is recommended for PKI?

In my research, I found some RFCs that have not been updated in over a decade, e.g draft-ietf-pkix-ldap-crl-schema-01. I also explored several public directories used in PKI (e.g. x500.bund.de) and ...
9
votes
1answer
578 views

Why does GoDaddy have four different certificate chain, G2, G3, G4?

I see from Godaddy they have multiple certificate chains https://certs.godaddy.com/repository GoDaddy Certificate Chain GoDaddy Certificate Chain - G2 GoDaddy Certificate Chain - G3 GoDaddy ...
1
vote
2answers
136 views

Why/when would a CA make a generated public key available to the public at large?

I'm confused about this section in my CEH security exam training material: A CA is able to perform a number of roles in addition to the validation process outlined here. Some actions that a CA is ...
2
votes
2answers
66 views

Why not to use the same subordinate issuer CA for generating certificates that will be used for different things?

Microsoft has recommended my organization to use different subordinate issuer CAs in order to issue certificates that will be used for different things. For example, they recommend to use a CA for ...
6
votes
3answers
277 views

Why should my certificate signing request be signed by my private key?

Why should my certificate signing request be signed by my private key? Even if I obtain a bogus certificate out of someone else's public key, that is going to be useless, since in SSL the ...
3
votes
1answer
99 views

Designing a PKI environment

For our company I was given the task to design a durable, structured PKI environment for mainly client authentication purposes. We need a Root CA with a couple of Intermediate CAs, like this: ...
5
votes
2answers
189 views

How do I produce a CA signed public key?

I have a need to have somebody else encrypt secret data with my public key that I can then decrypt with my private key. I have produced an RSA private/public key pair with OpenSSL gave them the public ...
3
votes
1answer
56 views

What happens if an OpenPGP subkey gets compromised?

In my GnuPG keyring, I have a primary key for creating keys and three subkeys: two for encryption and one for signing. All of then have the same password. If a subkey gets compromised, is it possible ...
1
vote
0answers
27 views

Can there be two certificates with a same serial number in the world? [duplicate]

Recently I came across this odd question. I hope, Serial number is unique across certificates signed by a particular CA. So is there any chance that two different CAs sign two different certificates ...
1
vote
1answer
117 views

PKI management with easy-rsa

I recently setup an OpenVPN server with easy-rsa and have questions about certificate revocation: In the event that someone's private key gets compromised and I have to revoke the certificate with ...
1
vote
2answers
84 views

What exactly does `ssh -T user@domain verify` do?

The example I'm specifically thinking of is: ssh -T git@github.com verify Looking at the docs (man ssh) I can see that -T is the flag to "Disable pseudo-terminal allocation", but what implications ...
1
vote
1answer
170 views

How does letsencrypt's ACME work?

I found the technical paper on ACME's inner workings, but I still feel a bit confused about the ways Let's encrypt's Domain Validation works. From what I already know, verification can be performed ...
0
votes
0answers
35 views

PKI, one sub CA for each certificate type VS one for all the certificates type

I'm trying to set a PKI where I can find 3 types of certificates: A client certificate to use in HTTPS communications A web server certificate to use in HTTPS communication A VPN certificate to use ...
1
vote
2answers
66 views

PGP Key Signing Robot DKIM Verified Emails

It occurred to me that DKIM verified emails, from major players (e.g., GMail), could open the door to more modern OpenPGP robot key signing authorities. The idea would be to ask people to send a key ...
1
vote
1answer
45 views

Prevent credential roaming for certain accounts/certificates?

I want to use credential roaming in Windows 7, 8 and 10 for EFS certificates, so users can access their encrypted files from any computer they login to. However, some of these users will also have ...
14
votes
1answer
1k views

How secure is “Let's Encrypt”?

I just configured and installed a free SSL certificate from Let's Encrypt. It's great, and very easy to set up. However in this post-Snowden era, I was wondering how secure this really is. For ...
1
vote
1answer
28 views

Certificate binary matching

Is it an industry practice to do a binary matching of client public certificate when doing SSL with client authentication? I was thinking that if the client can successfully do the SSL handshake, ...
4
votes
1answer
126 views

Centralized key management for IOS and Android Code Signing

What is the best way for an enterprise to manage code signing certificates? The default seems to be that Apple and Android keys get stored by each developer on their machines. I see systems like ...