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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55 views

Understanding Digital Certification as as a whole starting from a normal http request

I am very new to security and i do not come from an IT background. Please pardon me if i ask some very simple and questions that don't make sense. I am trying to understand the difference between ...
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1answer
43 views

Managing/Deploying a code signature certificate - Java Applet

I wonder how to manage/deploy a code signature certificate used by the JVM in a corporate context. Suppose you signed a Java applet (executed in browser by corporate users), how to deal with the ...
4
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1answer
71 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 ...
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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 ...
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3answers
1k 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 ...
7
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4answers
328 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
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3answers
839 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? ...
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0answers
35 views

A potential possibility of improvement of PKI for personal communications

In countries like Germany each citizen has an identity card that is issued by the registration authority. Since the identity of a citizen is, in a sense, created by that authority via assigning him ...
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0answers
32 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: ...
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6answers
1k 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 ...
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2answers
3k 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 ...
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3answers
456 views

P12 - Extract public part (certificate) without knowing the p12 password

I would like to extract the public part of a revoked P12 which doesn't belong to me. I can't open it with KeyStore Explorer because I am prompted for the password, is it possible with OpenSSL ? The ...
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2answers
1k 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 ...
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1answer
118 views

Is it possible to do Public Private Key Encryption on a chip (hardware)?

Does a chip exist which will take input data and output encrypted data in a public private key scheme, where the public key is on the chip and the private key is located remotely? The ultimate goal ...
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2answers
46 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 ...
3
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1answer
33 views

Extend hierarchical PKI

The figure below shows four simple hierarchical PKIs. A, R, H and N are trust anchors of their PKI. I am supposed to add exactly one certificate so that T trusts G, but not D. Furthermore R must ...
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3answers
8k 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 ...
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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 ...
2
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2answers
433 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 ...
23
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4answers
32k views

Expired SSL Certificate Implications

What are the security implications of an expired SSL certificate? For example if an SSL certificate from a trusted CA has expired will the communication channel continue to remain secure?
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1answer
117 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 ...
2
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3answers
47 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 ...
2
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1answer
41 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 ...
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1answer
23 views

Generating shared secret key using existing receivers public key and senders private key

I have the public key of the receiver, and the private key of the sender. I want to generate a new key by using the receivers public key and senders private key (also known as the signing key) to ...
3
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1answer
54 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 ...
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2answers
37 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 ...
0
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1answer
35 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 ---------------------- ----------------------- ...
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1answer
36 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 ...
8
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2answers
106 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
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0answers
44 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
102 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 ...
3
votes
1answer
48 views

Verifying cryptographically signed files when the key has been revoked

This is mostly a question out of idle curiousity. If I use my private key to sign a file today, forming a signature, and distribute that signature with the document to someone they can then use my ...
3
votes
2answers
89 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 ...
4
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2answers
85 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 ...
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2answers
138 views

What if the Local Windows Cert Store is Compromised?

The diagram below illustrates chaining digital certificates up to a publicly trusted Root Certificate: I have been researching how trusted root authorities (such as GlobalSign or Verisign) are used ...
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1answer
74 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 ...
527
votes
3answers
266k views

How does SSL/TLS work?

How does SSL work? I just realised we don't actually have a definitive answer here, and it's something worth covering. I'd like to see details in terms of: A high level description of the ...
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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
58 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
89 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
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1answer
85 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
202 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 ...
2
votes
2answers
2k 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 ...
98
votes
5answers
67k views

What is certificate pinning?

I'm superficially familiar with SSL and what certs do. Recently I saw some discussion on cert pinning but there wasn't a definition. A DDG search didn't turn up anything useful. What is certificate ...
5
votes
2answers
65 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
79 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: ...
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8answers
2k views

Is there such a thing as public key steganography

One of the drawbacks of traditional steganography is that both parties need to exchange a secret key. Encryption had this problem too but circumvented this with public key cryptography. Are there ...
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4answers
55 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 ...
8
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3answers
889 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
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2answers
279 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 ...