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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21
votes
8answers
4k views

Can a HTTPS connection be compromised because of a rogue DNS server

If I'm visiting (just a desktop PC, client side) a site that has a valid HTTPS cert/connection, that can it be compromised if I'm using a rogue DNS server (not deliberately, I'm concerned about an ...
4
votes
2answers
135 views

Should I add picture(s) to my OpenPGP key?

I'm toying with the idea of creating a pair of OpenPGP keys, and I'm wondering if I should include a picture or two. I know it will make my key a lot bigger, but is it still worth it? I'm thinking of ...
-4
votes
2answers
79 views

Does SSL doesn't work without a secondary Symmetric/Asymmetric session key?

I keep reading that Symmetric session key is used in SSL after handshake only for faster performance but isn't true a secondary session key either Symmetric or Asymmetric key generated by the client ...
1
vote
2answers
212 views

Difference between KMS and PKI

While the PKI System deal with digital certificates life cycle and Key Management System (KMS) deal with keys life cycle. What is the the fundamental difference between them? Is it possible to ...
7
votes
2answers
975 views

One website - two different SSL certificates: two different CA's

I have seen multiple questions focusing on multiple certificates for a single domain (e.g.: a.com/example and a.com/example_one). However, what stops an individual from purchasing a certificate and ...
-2
votes
1answer
104 views

how to make non HTTP Applications PK-enabled

I have a server application that is using Winsock2.0 for client communication, this application is a service. The client is also a Windows desktop application and performs few operations. For example ...
23
votes
5answers
5k views

Are self-signed certificates actually more secure than CA signed certificates now?

Are self-signed certificates actually more secure than CA signed certificates now? I ask this because recent leaks about the NSA spy programs and the secret FISA courts mean that the US government ...
2
votes
3answers
212 views

How to deliver an encrypted message to multiple recipients without revealing keys

Let's say I have generated a private and a public key. I create a message and encrypt it with the public key. I deliver this encrypted message and a private key to multiple recipients. Why would I do ...
4
votes
1answer
74 views

Cross-certification between worlds like X.509 and PGP?

Sometimes it can be advantageous to use existing trust relationships in one certification world - X.509 or PGP - to create trust in the other world. At the lowest level I can always take an X.509 cert ...
0
votes
0answers
90 views

Certificate policies extension in Root CA and Issuing CA

I am building new CA chain and PKI and I actually don't fully understand how I should include certificate policies (CP) and certificate practice statements (CPS) as extensions and how to work with it ...
36
votes
3answers
25k views

What are the risks of self signing a certificate for SSL

Let's say I sign a SSL certificate for myself, and I'm not using a certified CA. What are the risks and/or threats of doing it?
0
votes
2answers
127 views

PKCS#12 File - security impacts when imported in Web Browser or Windows Store?

When a PKCS12 file is imported into a Web browser or Windows store the user is prompted for private key password. How does the browser or operating system manage this password? Is it secure?
0
votes
1answer
77 views

How secure is this security protocol? [closed]

I'm developing an application that will encrypt a bunch of files the client has on their machine and then send them to a server, to back them up. I need to encrypt the files so that other clients/...
5
votes
1answer
91 views

How can I demonstrate that 3 independent root CAs validated my domain?

I am concerned about the hacking of a root CA and want to buy 3 SSL certs from completely different providers who will independently validate my identity. Then at presentation time, I will send all 3 ...
21
votes
4answers
2k views

Cloudflare's free SSL options require trusting them; what could they do to change that?

Cloudflare offers 3 free SSL options: Flexible SSL, Full SSL, and Full Strict SSL. The article “CloudFlare’s great new features and why I won’t use them” explores the shortcomings of the Flexible and ...
5
votes
3answers
2k views

Digital Signature and Verification?

AFAIK , When Alice wants to write a message to Bob -- she uses Bob's public key and encrypt the message - and then Bob - using his private key - use to decrypt it. So public key is used to decrypt ...
6
votes
4answers
347 views

Renew digital certificate

If I have deployed a digital certificate on a webserver and if it needs to be renewed then what steps do I need to follow? Will I need to generate a new longer public key private key pair? Why do ...
6
votes
3answers
1k views

What if someone steals a Certificate authority's private key? [duplicate]

What if someone could steal a Certificate authority's private key? I know this will (probably) never happen, but what would happen to the certificates that were already signed with this private key? ...
1
vote
0answers
286 views

Certificate Transparency, TLS Extension method of serving SCT's

I was curious about how to supply certificate transparency from my web server. There are 3 ways certificate transparency information can be delivered to the client's browser (Source: http://www....
11
votes
6answers
2k views

Are there any hardware HSMs that can host/run custom applications using the HSM processor(s) within the hardened security boundary?

It seems that the majority of commercially available hardware HSMs are only designed to allow authenticated users to generate, store, and use cryptographic keys with various cryptographic algorithms ...
4
votes
2answers
4k views

Checking SSL/TLS servers for NULL encryption support

I have a web server supporting SSL 3 and TLS protocols, the following are the supported cipher suites: TLS_RSA_WITH_RC4_128_MD5 TLS_RSA_WITH_RC4_128_SHA TLS_RSA_WITH_3DES_EDE_CBC_SHA How can I ...
7
votes
2answers
2k views

Why is ECC more vulnerable than RSA in a post-quantum world?

Forgive me if this should be in the crypto sub, but sometimes the answers there are very mathematical and I would rather have an answer which is a bit lighter on the math but still strong on the tech ...
1
vote
2answers
207 views

PKI cards - PIN and certificates

My company has introduced a PKI some months ago. We are now able to login in our laptops either with our Windows credentials or with a PKI smart card plus a 6 digits numeric PIN. A part from that we ...
25
votes
2answers
13k views

How to set up OpenSSH to use x509 PKI for authentication?

I do not mean simply putting the public RSA key of a x.509 certificate into ~/.ssh/authorized_keys - I'm looking for a way to set up a ssh such that x.509 certificates signed by a pre-defined CA will ...
1
vote
0answers
21 views

Relationship between the validity of license of an accredited CA (certificate authority and the validity of it's certificate? [duplicate]

To more clear, let's see my example: As I know, in Korea, the validity of a CA's license is only 2 years, but the validity of this CA's certificate is 10 years. Why is the valid time of the license ...
4
votes
2answers
2k views

How do session keys in public key cryptography work? [duplicate]

I have read that a session key is symmetric, and it is encrypted by recipient's public key; When "Bob" receives a message, does he decrypt it with his private key and he's then in possession of an ...
2
votes
1answer
150 views

What is the most secure way to digitally communicate between the U.S. and China?

What is the most secure way for two people to communicate digitally when one person is in the U.S. and the other is in China (likely being monitored)? Updated: Here's some additional info: The ...
3
votes
3answers
97 views

PKI usage in a cluster; per application instance or per application?

I'm having a cluster with nodes (let's call them A and B for the sake of example) running identical micro services (1, 2 and 3 - so the application 2 running on node A is called A2). The applications ...
4
votes
1answer
143 views

How to verify an OpenPGP key's ownership?

I've added the public key of Diceware creator (please use it as a practical example), I've added it by downloading diceware.wordlist.asc, and I didn't have his key and couldn't immediately find it to ...
5
votes
2answers
198 views

What do the terms used in OpenPGP keyserver SKS mean? (sig, sbind, sig3, exp2, Policy, …)

When viewing a key record in a public key server, such as this one, there are lots of keywords used: sig, sig3, exp3, Policy, sbind…). I understand that "sig" probably means a signature, but what's ...
1
vote
1answer
159 views

Confused about RFC 4492: difference between “ECDH-capable public key” and “ECDSA-capable public key”

As per section 5.3 of RFC 4492, I'm confused with the following table: Key Exchange Algorithm Server Certificate Type ---------------------- ----------------------- ...
1
vote
1answer
51 views

What does the letter in an OpenPGP key's bits definition (like 4096D) denote?

I noticed that when looking at OpenPGP keys on a key server, the key's bits definition is usually followed by a letter, as in "4096D" for example. However, there are also keys with other letters than ...
9
votes
2answers
332 views

Electronic identity and digital signatures - why they are different?

It seems (to me at least) that is is generally accepted that "electronic identity" and "digital signatures" are a different thing. For example, in the Estonian ID card there are two certificates - one ...
0
votes
0answers
170 views

How to add a certificate chain to a JKS

I want to setup a KeyStore which contains certificate-chains only. This is required by a PKE system which uses the PublicKey of the desired certificate for encryption an then sends the cipher to the ...
2
votes
1answer
103 views

Message and Key Security

I'm reading Post-Quantum Cryptography, and in the page 106 in the beginning of the Section 3 it says: In this section we consider the message security (opposed to key security) of code-based ...
2
votes
2answers
171 views

Internet Explorer - Advanced Properties for Trusted Root Certificates

If you go to IE -> Internet Options -> Content -> Certificates -> Trusted Root Certification Authorities. Now Click on some CA certificates and click on Advanced You can add properties to the ...
5
votes
2answers
154 views

What encryption and signature systems (don't?) allow for plausible deniability of the OP's key being used?

I need to prevent Mallory from blindly matching encryption and signing keys to messages Hypothetical scenario: A user creates a public key An encrypted or signed payload exists. With only public ...
1
vote
1answer
102 views

Is it complicated to deploy my own CA?

We want to implement a free solution to sign digitally internal documents. No legal value of this sign are requested. We want to consider to deploy an internal CA. Why is it always said that keeping ...
14
votes
2answers
2k views

How would I implement “Broadcast Encryption”?

I have a stream that I want to encrypt for broadcast to 10,000 subscribers. I know I should encrypt this data using a symmetric key; and also intend that this symmetric key will be rotated every 30 ...
3
votes
2answers
211 views

Using Different Algorithms in Single PKI

Assume the following Public Key Infrastructure: |Root CA (RSA) |-Sub CA (RSA) |-Sub CA (ECC) Is there any rational that explains why this would not be an acceptable implementation? Is the ...
5
votes
2answers
113 views

How do I prepare for Certificate Authority end of business?

We are deploying a security solution which uses certificates to validate documents. These certificates are issued by our government-authorized CA. What if in a distant future, the CA who provided us ...
1
vote
1answer
110 views

Should self signed wildcard certs be used?

I think this is more urban legend around where I work than anything. I do not see anything in RFC 2459 that specifically says whether or not they should be used or if there are any known problems with ...
3
votes
2answers
370 views

Is it dangerous to use the same key (RSA) for both encryption (PGP) and authentication (SSH)?

Alice wants to send an encrypted message to Bob, but she also wants to connect to Carol's server. Are there any dangers associated with using the same RSA key for both PGP and SSH (other than a lack ...
7
votes
2answers
6k views

Generating ECDSA certificate and private key in one step

Similar to how it can be easily done for RSA: openssl req -x509 -nodes -newkey rsa:2048 -rand /dev/urandom -keyout example.key -out example.crt -days 365 I'd like to generate a ECDSA cert/key in ...
5
votes
2answers
77 views

Understanding digitial certifications

q1) Does that mean that every time information is exchanged, both the original data + digital certification is sent? Meaning data + signature for each and every exchange. q2) Can any kind soul here ...
6
votes
2answers
90 views

Issuing certificates to two departments from same ROOT CA so one does not trust the other

Scenario: We have two departments within IT; Say Department-OLD and Department-NEW. A single internal PKI environment exists and a root CA (singular) is trusted by All endpoints. Problem: ...
0
votes
4answers
187 views

Generating SSH keys and sending the private key

I've been looking up on how to set up public key authentication between two hosts on my LAN. I am going to be using a pass phrase with my key pair. A lot of tutorials instruct me to generate the key ...
11
votes
3answers
1k views

Can I expose a passphrase-protected private OpenPGP key? [duplicate]

I have created a 4096-bit key-pair using GnuPG. Can I expose the passphrase-protected private key to an untrusted system? E.g. can I put that key in my Dropbox account or send it to myself as an ...
3
votes
2answers
296 views

Should I be concerned at the lack for transparency by Microsoft which quietly added 17 root certs?

This week it was noticed that Microsoft apparently very quietly pushed out 17 new trusted root certificates (Infoworld Article). The lack of public announcement seems a bit strange. Is anyone aware ...
2
votes
4answers
1k views

Is it neccessary that website certificate must have site URL?

While working on a scenario, I got the error message "Server's certificates doesn't match the url". Is it necessary that the certificate given from the website must have its URL? Is it necessary that ...