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7

If someone steals a CA's certificate signing key, the already signed certificates remain valid. But that doesn't mean they are not harmed. The whole point of certificates is that only a trusted party can produce them, so that when you see a certificate, you can be confident that it is valid and that you're talking to the entity you intended to talk to. If an ...


2

You are correct that it would not cause any harm to the certificates that were already issued, but it does call into question which certificates are still trustworthy, and which are not. It's safer and easier to just treat all certs issues by that signing key as "compromised" and re-issue them. In this case the CA's signing certificate would be revoked with ...


5

A normal CA has a procedure in place for this. it starts with invalidating ALL certificates signed with the key, Than have the CA make a new Root Key and Certificate. than do all the steps involving the setup of a new CA. After that is done, reissuing all certificates that were affected and still valid. A problem if this is not mitigated soon after the ...


3

SSL certificates provide two things: Authentication of the organization to whom the visitor is connecting (the organization is verified to be www.foobar.com) Confidentiality of the communication (data is encrypted using the public keys in the certificate) Concerning point 2, there's no difference in using a self-signed cert, a certificate issued from a ...


-2

No, it is even less safe. If you have no knowledge of security or of certificates you should not roll your own. (luckily its not as bad as running your own CA without knowledge) CACert helps you to get the proper values in your certificates so your safe from misuse. the web of trust also means the CAcert will be on par with a face 2 face audit form a ...


2

I will answer this in a two-level approach: General term answer and the specific SSL/TLS clarification in blockquotes. Public Key Cryptography (PKC) solves the problem of securely exchanging information without the need of previously agreeing upon a secret key. To be part of PKC, every agent needs to have a Private Key (which should only be kept by the ...


14

There is nothing at all wrong with running your own internal certificate authority; the vast majority of large companies that I have interacted with have their own internal CA. Advantages The nominal cost of a cert becomes nearly zero when amortized over enough systems and users; when you purchase certificates from an external CA, this will never become ...


1

I designed an image as Short answers of questions: for reading texts of the image open image in new tab for more details go to my previous answer.


3

Short answer: No. I think you won't be happy with only three CAs. Lots of clicking around certificate warnings. This will not make your browsing safer. Also reconsider what you are trying to achieve. I'm assuming, that you want to protect yourself from rogue and/or exploited CAs. So that means CAs that will issue certificates for google.com, etc, when ...


0

These certificates are of very little value. First of all, allowing them to generate the private key is very questionable. We have no details on how they do this or whether they retain this information - for all we know, they use the same private key for all certs or retain the key information, which may not be done in a secure manner (imagine what a rich ...


3

As an Introduction sentence: PKI(Public Key Infrastructure) and PKC(Public Key Cryptography) with together are considered as PKT (Public Key Technology). Short answers: for reading the image open it in new window Now is the time to answer the questions. 1. What is the difference between Public Key Infrastructure and Public Key Cryptography? I ...


8

Public Key Cryptography designates the class of cryptographic algorithms that includes asymmetric encryption (and its cousin key exchange) and digital signatures. In these algorithms, there are two operations that correspond to each other (encrypt -> decrypt, or sign -> verify) with the characteristic that one of the operations can be done by everybody while ...


1

Since we should all be familiar with the layers a la the OSI model: PKI sits atop public key crypto. The public referred to here is a misnomer, in the sense that it does not really mean a generalised audience, but that the keys, or at least the public key, can be in the open, and also by extension able to be freely distributed, though in reality this might ...


1

Until the early 1970's, the only way to encrypt and decrypt messages was using symmetric algorithms, in which the same key is used for both operations. The key has to be exchanged securely by some means before two parties can communicate privately. Public key cryptography, or asymmetric encryption, is a novel way to encrypt and decrypt messages using two ...


4

What is the difference between Public Key Infrastructure and Public Key Cryptography? How are they related? I think the difference between Public-key infrastructure and Public-key cryptography is pretty clear from their Wikipedia definitions (quoted after the tldr). TLDR: Public key cryptography is another name for asymmetric algorithms, while PKI is ...


-1

Public Key Infrastructure refers to the systems and processes for managing the exchange and validation of security certificates. Public-key cryptography provides the technical parts for the actual encryption/decryption, but PKI is what provides reasonable assurance that the certificate is from a valid and authenticate identity, and "vouches" for trust. In a ...


-2

While I do cite quite a few references the majority of your question(s) are available online. With that said a preferred resource would be to visit the OpenSSL Wiki for usability, attack vectors, algorithms & implementation questions, GAIC for performance, best practices and high level information and NIST for standards regarding the use of PKI as well ...


22

Certificates are signed and the cryptographic signature is verified; if the signature matches then the certificate contents are exactly as they were when the certificate was signed. This, of course, does not solve the problem, it merely moves it around. The complete structure is called a PKI. The certificates which are preinstalled in your computer (came ...


6

If a virus installs a new root certificate on your computer, and a spoofed website presents you with a certificate with a valid signature chain from that root certificate, then your computer will accept it as a valid certificate. But this shouldn't be seen as a problem with SSL/TLS -- if you have a virus with that level of access, then there are lots of ways ...


2

Some things to consider when dealing with TLS as a protocol. The payload of the communicating packet is encrypted. The 'dst' & 'src' packet attributes are not, which allows for any device within the network route to intercept your communication. Numerous attack against the SSL & TLS protocol over the years have allowed for the following attack ...


1

Don't panic. It's just different ways of building a certificate chain of trust. Both ending in a trusted root CA. But once with and once without going via an additional intermediate certificate. There exists more than one certificate with the CN "VeriSign Class 3 Public Primary Certification Authority - G5" And SSL-Tools.net has a list of them. There's ...


0

Any CA can emit (and use) a valid certificate for any domain. It doesn't mean it won't be detectable, as the certificate won't be identical to the genuine one, as they would need the private key (presumably securely held by the site being impersonated). Certificate pinning will detect it (either built-in the browser, as some do for select sites, or with an ...


1

There are some news articles about existing backdoors on CAs for use by Security Agencies, but the trustworthiness of these news must be checked, New NSA Leak Shows MITM Attacks Against Major Internet Services There is no evidence that shows the trusted CAs use their certificates for MITM attacks, because sooner or later will be identified or disclosed ...


0

Perhaps relevant is OpenSSL Certificate Authority Setup . I use this in development environments all the time -- but this is a completely untrustworthy CA. On the other hand, it means that developers who need certs for testing can get them immediately. I've even got a web front end, and a script for an OCSP, again because they are useful for testing. But ...


0

The reason that this is not usually fully automated is that CAs want to protect their own reputation and ensure that the person they are issuing the cert to is the actual owner of the domain (often by speaking on the phone with the applicant). There are different levels of validation / background checking that a CA can perform when issuing, the two main ones ...


1

While thinking about it, I can now definitively answer that some CA offers Web API allowing to automate part or all of the certificate generation / signature. Some concrete example of this are Digicert, GlobalSign, Gandi. Some other CA may therefore offer the same services, however you need to check: The available functionality, not all functions ...


1

Note that EV certs are not structurally different -- they are just a cert issued under a different policy. So you have to check the policy. See http://en.wikipedia.org/wiki/Extended_Validation_Certificate#Extended_Validation_certificate_identification You will need to do a fairly extensive table lookup, won't be native to openssl I'm afraid. This is ...


0

Your Option 2 is sufficient and cryptographically secure. If the CA's signature on the client's certificate validates (and the CA's signing keypair hasn't been revoked due to compromise) then yes, you can assume that the certificate is authentic - ie it was issued by your CA and hasn't been tampered with. Remember that a signature is an encrypted hash of the ...


4

simply because CA's predate TLD Registrars. The whole Idea of Certificates have there origins in the DAP times (Directory Access Protocol), When the Idea was more along the lines of Central Directories giving Authority to specific users from certificates. (I am paraphrasing here) For historical reference. the first DNS (BIND) is from 1984. Many years ...


3

It really depends on how your application/site manages the certificates and public keys, i.e. how often are the keys and certificates rotated. For example, if your site rotates the certificates very often, then you'll also need to update your application that often as well, if you are pinning the certificate. Whereas, in this use case, pinning public key ...



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