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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30
votes
4answers
22k views

How does PGP differ from S/MIME?

Is S/MIME an abstracted system for general MIME type encryption, whereas PGP is more for email? Why would I want to choose one over the other, or can I use both at the same time?
16
votes
4answers
3k views

Is it dangerous to publicly share ciphertext?

Alice wants to share a message with Bob, but Alice and Bob can never be in the same place at the same time. We can assume they both know each others public keys (or agreed on a shared key, if that ...
0
votes
1answer
127 views

Begin of Certificate/ End of Certificate dash “-----”

What significance does the dash "-" holds along with the line -----BEGIN CERTIFICATE----- or -----END CERTIFICATE-----. I checked multiple docs and linked RFC's as well but could not find the ...
9
votes
1answer
270 views

I want trusted SMIME certificates for 3rd parties. Is this a reasonable configuration?

I want to send out SMIME certificates with my emails, and want to deploy the following PKI Root01 (All EKU, All Constrants, No Restrictions) PolicyInt01 (Internal applications, not trusted by 3rd ...
4
votes
2answers
250 views

Explicitly prohibit an intermediate CA certificate on OpenSSL

How do you explicitly not trust a particular certificate (especially, CA certificate) for OpenSSL? On NSS-based applications, one can install the cert with trustarg p: prohibited (explicitly ...
-1
votes
2answers
252 views

How do openvpn/easy-rsa generated keys map to RSA algorithm variables?

I was reading up a little on openvpn and pki infra and am confused by some of the questions posed by my colleague. :) This answer did help me understand more: ...
7
votes
7answers
4k views

Is Spoofing a CA signed certificate possible?

I had never thought about this situation before, I may be completely wrong but I am going to have to clarify it anyway. When a communication starts with a server, during the client handshake, the ...
1
vote
1answer
60 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 ...
0
votes
1answer
52 views

CSR signing follow up question

This is a follow up question , after getting a signed certificate from one CA. researched a lot , but no luck. After getting the CA reply, While downloading the certificate, it popped up saying ...
2
votes
1answer
46 views

Https certificate change effects on established secure channels

I've a question regarding https certificate changes. Does anyone know any side-effects to changing the certificate, one signed with RSASHA1 to one signed with RSASHA256 for ex, while users already ...
1
vote
5answers
172 views

multiple private keys for single public key

I am currently working in security in mobile ad-hoc networks I have several clusters, and I want from the cluster head to send some data encrypted with its public key ,to the cluster members. I assume ...
15
votes
1answer
30k views

Can a CSR be created in OpenSSL with SHA2?

Can a CSR be created in OpenSSL with SHA2? If so, what would the command be and what does this tell the CA, if anything? If you could create a CSR using SHA2 would it "tell" the signing CA to use it ...
3
votes
2answers
89 views

CSR Signing simulation

Tried a lot get my test csr signed from root CA(trial versions option), somehow i am not getting it dues to some of their internal check. Few questions that cropped up Can i somehow signed that ...
18
votes
4answers
12k views

Checklist on building an Offline Root & Intermediate Certificate Authority (CA)

Microsoft allows a CA to use Cryptography Next Generation (CNG) and advises of incompatibility issues for clients that do not support this suite. Here is an image of the default cryptography settings ...
3
votes
2answers
72 views

Certificate pinning and the key distribution problem

I (think I) understand the concept of certificate pinning. However, I'm wondering if, in the worst-case scenario: is certificate pinning any more secure than the hierarchical trust model it is built ...
3
votes
1answer
75 views

Ability to determine which PGP public keys a message has been encrypted for?

Is it possible to determine, given a PGP message that you can already decrypt, to determine which other PGP keys that message has also been encrypted for?
1
vote
1answer
111 views

P12 private key vs private key file : what is more secure?

The question is a bit tricky because they don't have the same purpose but : Do both kind of file face the same security issue concerning private key protection : password strenght ? (PBKDF2 as both ...
3
votes
1answer
106 views

Clarification needed on CSR signing process

There doesn't seem to be a lot of in-depth information on the certificate signing process other than: Key Management Interoperability Protocol Usage Guide Version 1.2 (PDF) RFC 2986 - PKCS #10: ...
1
vote
2answers
106 views

Can revoked certificates be “lost” if the base CRL is updated before expiration?

Assumption Suppose I have a CA that issues a base and a Freshest CRL. I also understand the Freshest CRL to be a Delta of revoked certs in the base. I also understand that clients should pull the ...
0
votes
0answers
46 views

What is the minimum acceptable time for “Freshest CRL” to be updated?

I'm working with MSFT CA, and not sure if this behavior is the same across all CAs, but when I run certutil -CRL, the base revocation cert is updated weekly, and the Freshest CRL (the differential) ...
4
votes
2answers
108 views

How should I document my Public Key Infrastructure?

I'm preparing to document a 3 tier PKI (with multiple second level policy CAs) and want to create a document that is useful, technical, and not too overwhelming to the non-PKI expert. I suppose the ...
1
vote
0answers
26 views

What are some scenarios I would use MSFT Certificate Enrollment Web Services?

The Certificate Enrollment Policy Web Service and the Certificate Enrollment Web Service are made for non domain connected machines to retrieve certificates of various kinds. When setting this up, I ...
0
votes
0answers
28 views

Distribution of key by server

I have read that in asymmetric cryptography, a system admin can generate key pairs on the server. After that, the users will be given the generated key pairs and this is an efficient way of doing this ...
2
votes
1answer
101 views

How do Client-specific keys and Certificates work?

I have clients that communicates with my server. Clients sends it unique id (guid) to server with its request over a secure https channel. Also to increase security I use my own private-public key ...
0
votes
1answer
41 views

public key formats [closed]

I have the following PEM format public key: -----BEGIN PUBLIC KEY----- MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDguwHaldTclMAFg1BQ45Q8DPIc ...
2
votes
1answer
6k views

What is the deal with Valicert SSL root certificates?

Does anyone know what the status of the "Valicert Class 2 Validation Authority" root certificate is or what's going on with Valicert in general? I've heard that that cert has been deprecated, no ...
1
vote
1answer
220 views

How do PGP keyservers synchronize the keys?

I want to know technical details about how public PGP keyservers synchronize the keys. If I send my key to one keyserver, how exactly does it "travel" to all the other ones? Who sends it to who and ...
2
votes
2answers
80 views

Does an alternative approach to PKI technology exist?

Currently all of the network is using PKI standards and we are facing many problems. I don't mean every time and if new technologies arise we will also have to face the same, but for my curiosity. ...
11
votes
1answer
8k views

4096 bit RSA encryption keys vs 2048

Where do 4096 bit RSA keys for SSL certs currently stand in terms of things like CA support, browser support, etc? In the overall scheme of things is the increased security worth the risk of 4096 bit ...
1
vote
1answer
101 views

What is the purpose of the CA-BUNDLE on a webserver?

So I purchase a certificate from DigiCert. The process goes like this: Generate private key and CSR on web server. Submit CSR to DigiCert. Get a signed certificate back as well as their root ...
1
vote
1answer
89 views

Why should I have my GPG key expire? [duplicate]

When creating a key pair using gpg it asks me for an expiration date: $ gpg --gen-key Please specify how long the key should be valid. 0 = key does not expire <n> = key expires ...
2
votes
4answers
770 views

If a MITM has your public key and you are SSH-ing through the MITM, what is the maximum attack it can perpetrate?

Firstly, let me start by saying that I am not attempting to hack anyone or anything (not that I would know how or where to begin, if I were). For illustration purposes, let's call the primary key ...
-4
votes
2answers
283 views

Is “HTTPS” ~100% secure? [duplicate]

Assuming that we have a "green bar connection" to a website, e.g.: Is an attacker still able to sniff our traffic? How secure is a user from man-in-the-middle attacks when he has established a ...
1
vote
3answers
73 views

Secure tunnel set up in an office environment

Suppose I am a rogue employee and I want to syphon some sensitive data out of the office and I only have office internet access for this. My office internet access needs to go through a proxy server, ...
0
votes
1answer
135 views

Two-factor encryption model [closed]

Please some on help me to understand this "Are you ready for this? With the two-factor encryption model your data is protected two-fold. First, a unique key is generated, encrypted, and turned into ...
2
votes
2answers
122 views

How can I create my own public certificate using openssl?

I have a public key/private key pair i generated using two primes p and q. I now need to use openssl to sign and create the certificate. I heard req utility and wrote this from the man pages. openssl ...
4
votes
1answer
40 views

Mail Signing Certificate – What are the impacts when revocated?

Suppose I open a signed mail on 1st January 2000, signature is OK. What about this two cases : 1) If next CRL is to be published one week later, I found it strange that it is “probably” valid until ...
0
votes
0answers
19 views

why DH is unbreakable and what are the facts that leads to strong DH? [duplicate]

I am new to DH and learned the basic about DH working and suspecting it can be breakable by normal MIM , then how we can use DH in plain http for sharing secret. correct me if i am wrong.
0
votes
1answer
44 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
447 views

Sign PKCS#7 and verify PKCS#7 signature with OpenSSL

If someone have to transfer X.509 certificates in a single bundle, usually, it is recommended to pack them into PKCS#7. And content of PKCS#7 can be signed. OpenSSL allows to pack certificates into ...
12
votes
1answer
1k views

Relationship between RSA, Diffie-Hellman Key Exchange, PKI and X.509?

I am getting confused with RSA, Diffie-Hellman Key Exchange, PKI and X.509v3. I took a look of RSA's mathematics algorithm, it seems like a encryption algorithm, right? Generating public key and ...
3
votes
3answers
340 views

Corporate PKI - SHA1 deprecation

Here is the context. Suppose you have a corporate PKI with : AC_Root (offline in safe store - SHA1 signature) SubRootA and SubrootB (offline in safe store - SHA1 signature) SubSubRootC, SubSubRootD, ...
10
votes
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 ...
4
votes
2answers
176 views

Verify digital signature without key public key in signature

When receiving emails, I sometimes see the following: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I found an integer overflow in PHP, in the conversation of dates to "Julian Day Count" function. ...
1
vote
1answer
49 views

Does SSL/TLS have the feasibility of detecting malicious things during transmission? [closed]

As per my knowledge the current implementation of SSL/TLS does not have the capability to identify the data is malicious or not during the transmission or before encrypt the data. If its have , kindly ...
2
votes
1answer
549 views

CSR from IIS 8 and Keeping my Private Key a Secret

I've been trying to understand something. When you generate a CSR from IIS, how is the private key kept as a secret, or is it? Do CA's email you a certificate that includes your private key? Because ...
1
vote
1answer
52 views

Can a PKCS12 file be distributed over insecure channel?

Is the PKCS12 only as secure as the password protecting private keys ? Can I distribute the p12 file over an insecure channel ?
9
votes
8answers
536 views

Authencity of information displayed on an untrusted device

Suppose I have a (bluetooth/usb) device which needs to displays information on an external pc/phone. Is there a simple and effective method to garantuee that the information displayed hasn't been ...
4
votes
3answers
143 views

How can I create a unique identifier that can not easily be reversed?

I've been working on the design of a longitudinal study and one requirement is: all participants will have a unique identifier that is not reversible from the data storage/analyst side of the study ...
0
votes
1answer
206 views

PGP Key publishing on MIT PGP Public Key Server [duplicate]

I have a public pgp key, so that users can send me an encrypted message. Ofcourse, any user that wants to send me a message, wants to verify that the public key (s)he has, really belongs to me. From ...