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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8
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10answers
7k views

How can I share files with other individuals using the cloud in a secure way?

I would like to use a dropbox because it is easy and convenient. But I want to encrypt the files with the public key of the intended recipient, so he will be the only one who can access the data in ...
10
votes
2answers
3k views

OCSP and CRLs: Specified in CA or client certificate?

Here's an example PKI setup: * Root CA (offline) * Issuing CA * Client 1 * Client 2 I'd like to specify a CRL distribution point for CRLs generated by Root CA, and an OCSP URL for Issuing ...
0
votes
1answer
419 views

Enterprise Encryption Considerations

What are the different aspects to consider for Enterprise Encryption policy? So far the resources I have are: https://www.owasp.org/index.php/Cryptographic_Storage_Cheat_Sheet http://esj.com/...
6
votes
4answers
546 views

What fields in a suspicious certificate should I look at?

Looking at a certificate for a web-site (in Windows/Google Chrome) I see it lists the following fields Version Serial number Signature algorithm Issuer Valid from Valid to Subject Public Key Basic ...
7
votes
2answers
1k views

Two certificates on smart card

I have a question regarding Swedish gov eID (but I guess it is a pki/smart card general question); Why is there two certificates/keys on the card? Background: In Sweden you can have a "citizen ...
6
votes
1answer
9k views

openssl verify signature

For S/MIME, I now know I can verify PKCS#7 detached signatures with: openssl smime -verify -in detachedsign.pem -content content.txt But what about non-MIME messages? So if I sign the message Hello,...
3
votes
2answers
493 views

Null content digitally signed message

IA technical specification I'm following requires me to send: The Digital Signature must be in the form of a null content Digitally Signed message (i.e. a PKCS#7 object containing the signature ...
9
votes
2answers
440 views

Why is there no Domain CA?

I was asked to deliver a signed SSL certificate for an IIS server for a client. I have previously done this for the same client/domain before, so it start to seem like an unnecessary expense to hold ...
28
votes
4answers
42k 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?
6
votes
3answers
2k views

How and when should I use OpenSSL for IT Security? How do I understand the output?

I'm discovering OpenSSL, and already used it to diagnose a faulty SMTP TLS connection, but I'd like to get a better / full understanding of the tool and how to use it. What resources should I use ...
38
votes
3answers
26k 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?
26
votes
4answers
39k views

how digital signature verification process works

I am not able to understand that how the digital signature is verified. I know that digital signature will be attached to the message and sent by sender to receiver. then receiver uses the public key ...
39
votes
4answers
31k 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?
5
votes
2answers
817 views

How practical is a certificate's “basic constraint” property in protecting my HTTPS / SSL session?

Suppose a leaf node creates a certificate for a different domain, acting as a CA. Do most popular frameworks, or SSL chain validation tools verify the constraints? Are there any I should be ...
6
votes
3answers
194 views

Guarding against rogue certificates

There has been a lot of news recently about certificates being falsely issued (due to the issuing authority having poor system security!). Apparently the targeted users were mostly Iranians, but it's ...
16
votes
4answers
30k views

Recommendations for a Certificate Management tool for Linux [closed]

A client is looking to roll out OpenVPN to all its mobile employees and will use certificates on both the server and all clients. This creates a new challenge to manage all these certificates and ...
6
votes
3answers
445 views

Why are CA's signing keys available on the internet

I am not very knowledgeable about CA certificates, but I thought these things mainly said "The public key for bank X is Y, and this is verified by CA Z". Once you've bought this certificate, there is ...
12
votes
4answers
3k views

Multiple CAs signing a single Cert/CSR?

Just saw this suggested on Slashdot So I've seen quite a few people wanting a switch to self-signed certs (who IMO mostly don't understand what making that secure actually involves), and an idea ...
4
votes
3answers
1k views

How are possible uses for X.509 (SSL) certificates denoted?

X.509 certificates can be used for servers, clients, email, code signing and more applications. http://twitpic.com/6gdxaq indicates that a certificate can have different of these 'capabilities' on it -...
32
votes
3answers
3k views

What is an SSL certificate intended to prove, and how does it do it?

If I get an SSL certificate from a well-known provider, what does that prove about my site and how? Here's what I know: Assume Alice and Bob both have public and private keys If Alice encrypts ...
8
votes
3answers
889 views

Does the SSL encryption strength or validation level of a website really matter?

When looking to get an SSL certificate one is presented with a lot of options. For example lets take Network Solutions since they have a nice comparison chart. Immediately there seems to be 4 major ...
3
votes
1answer
945 views

What kind of certificate do I need to be able to make and sign my own digital signing certicates?

At build time for a program, I would like to generate a new key pair, and create a certificate that will be embedded (securely) into the program. The purpose of the key pair is to digitally sign an ...
7
votes
2answers
515 views

Geographic equivilent of RFC 3161 (X.509 PKI Time-stamp Protocol)

First time poster here, hope to be around more often. I'm in need of a cryptographically secure 'stamping' system that allows not only time but also location to be attached to data, while still ...
16
votes
3answers
3k views

What happens when an Intermediate CA is revoked?

Currently I'm working on a certificate manager that allows our product to securely connect to remote webservices (over TLS/SSL). For security, we use Certificate Revocation List checking (or CRL-...
22
votes
6answers
3k views

Shouldn't GPG key fetching use a secure connection?

If I run this for example: gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys 0xFBB75451 then does the importing occur in a secure way? I mean does it go over only secured connections? (HKP?) ...
12
votes
4answers
2k views

Why isn't OCSP required by default in browsers?

According to the following screenshot, taken from firefox-3.6.17-1.fc14.i686, Firefox has an option to fail closed when unable to connect to OCSP servers. Can someone please explain why this isn't ...
22
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 ...
8
votes
1answer
383 views

distributing files to VPN partners

suppose i've created VPN certificates for a certain VPN-RoadWarrior-Client, expressed in the files VPN-RoadWarrior-Client.key and VPN-RoadWarrior-Client.crt*, however VPN-RoadWarrior-Client is ...
9
votes
2answers
1k views

security of PKI, Certificates, certificate authorities, forward secrecy

I want to understand how certificates add to the security of information exchange. Suppose i have a encrypted bidirectional connection between Alice and Bob, using a public key/private key pair. As ...
70
votes
7answers
77k views

Certificate based authentication vs Username and Password authentication

What are the advantages and drawbacks of the certificate based authentication over username and password authentication? I know some, but I would appreciate a structured and detailed answer. UPDATE ...
8
votes
2answers
518 views

Is there a way to negotiate a secret between 2 parties with no prior knowledge?

Is there a way for 2 parties to negotiate a shared secret (for example, a session key) without having a pre-shared knowledge? SSL does this by using asymmetric encryption. Is there any other way to ...
19
votes
3answers
5k views

Computationally simple, lightweight replacement for SSL/TLS

Target hardware is a rather low-powered MCU (ARM Cortex-M3 @72MHz, with just about 64KB SRAM and 256KB flash), so walking the thin line here. My board does have ethernet, and I will eventually get ...
8
votes
1answer
2k views

Moving from a one tier to a two tier Microsoft Certificate Authority hierachy

Right now we have a single Microsoft Enterprise Root CA which issues certificates to our VPN users for two factor authentication. We're planning to extend use of the CA to issue certificates for RDP ...
13
votes
1answer
3k views

Renewing Microsoft Certificate Services Root Certificate

We currently have Microsoft Enterprise Certificate Server installed on a domain member machine which issues 1 year certificates to users for authenticating to VPN. We'd like to start issuing web ...
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 ...
5
votes
1answer
990 views

Thunderbird - what happens if Gmail SSL cert gets spoofed?

I use a good MUA: Thunderbird [to read/reply to my emails on Gmail]. So: what happens, if i go to a place, where is public wifi, and someone tryes to sniff my password/username/emails? Questions: -...
16
votes
2answers
1k views

Encryption and the “security time decay” of prior encrypted data

This question is on the assumption that any data once encrypted, may (eventually) be decrypted through Brute force (compute power/time) Exploits in the cryptography used Theft of private keys ...
8
votes
3answers
2k views

Certificate authorities for a PKI

Some people think the certificate authorities for a PKI should be the government, but others think certificate authorities should be private entities, such as banks, corporations, or schools. What are ...
68
votes
12answers
9k views

How feasible is it for a CA to be hacked? Which default trusted root certificates should I remove?

This question has been revised & clarified significantly since the original version. If we look at each trusted certificate in my Trusted Root store, how much should I trust them? What factors ...
9
votes
2answers
814 views

PKI solution vendor selection

What would you look for in a (X.509-) PKI solution, and why would you look for that, given the following constraints: Available programming/sw-engineering know how is limited (ie, "OpenSSL with a ...
6
votes
4answers
348 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

Certificate chain

For my computer to verify the identity of a certain certificate should it have all the certificates up to the root certificate?
11
votes
2answers
6k views

SSL Certificate revocation check

In the SSL protocol I don't see where the certificate is checked for revocation status. https://developer.mozilla.org/en/Introduction_to_SSL Is the Certificate Revocation and Status Checking not ...
0
votes
2answers
201 views

Create a certificate signing request [closed]

can someone please tell me a few tools that can be used to create a CSR ?
7
votes
2answers
6k views

What is an intermediate certificate authority?

What is meant by an "intermediate certificate authority?"
10
votes
3answers
6k views

How does an SSL server prove its identity?

This document says that a challenge response authentication proves the servers identity. But is a man in the middle attack still possible if the client does not verify domain name ? Please help me ...
29
votes
4answers
25k views

How to achieve non-repudiation?

If I have a message that I need to send to another person, how do I achieve non repudiation ? Is digitally signing the message sufficient ?
25
votes
2answers
12k views

How does RSA encryption compare to PGP?

On this answer ck says RSA and PGP are different. What you are essentially asking is how do I run my petrol car on diesel? The answer is you can't. I would be interested in a more ...
6
votes
3answers
2k views

Safe implementation of sharing encryption secrets (username, password) in the cloud

I'm building a multi-tenant (cloud) environment that needs to push out (or make available for download) configuration files for agents (background services) that receive this information. One of the ...
5
votes
2answers
3k views

Dealing with expired or revoked signing certificates with Infopath documents

Suppose I have an Infopath form that is digitally signed today by a valid, and active user. When that user leaves the company, we disable the account and revoke the certificate. This causes a problem ...