A piece of data used in public key cryptography that contains identifying information (i.e. email address or web address), a hash of a public key, and a digital signature that authenticates the data in the certificate.

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Web Certificate invalidation - You might be connecting to a website that is pretending to be [Site name]

Recently while trying to log-in to Facebook this notification starts to appear: At first I ignored it (by pressing Continue), but it started to popup every time I navigate through the website! I ...
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425 views

Single domain SSL certificates, actually support 2 subdomains?

While browsing for SSL certificates, specifically domain validation type (the cheapest), I noticed that they advertise as valid for a single domain/subdomain, but then I noticed that they are valid ...
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Is an AIA or CRL useful / required at the Root CA if that Root is used to cross certify another PKI?

Suppose I have several independent PKIs that are used Two internal PKIs: One with SHA1 support the other with Suite B algorithms. A partner who I trust and have a policy map with. Since both my ...
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380 views

Does the following data stream look secure to you?

I understand the basic concept of SSL but maybe I am missing the point. Please could someone take a look at the following part of a test log to a server and tell me if it looks secure. My concerns are ...
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192 views

TLS server key: possible to sign another TLS server key?

If I have a valid (verifiable) certificate C_K_s that links the server key K_s to "www.example.com", is it possible to : use K_s to sign K_d, and let S_K_d be this signature use K_d as the TLS ...
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Can a certificate have multiple chains and multiple self-signed roots?

The following MSFT document has this paragraph: All possible certificate chains are built using locally cached certificates. If none of the certificate chains ends in a self-signed ...
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753 views

How secure is TOTP key on phones?

Our company is considering several options in moving to MFA with software OATH TOTP or yubikey OATH OTP. In regards to where the secret is stored, I'm aware that a yubikey or similar hardware device ...
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643 views

Is there any research on which SSL certificate authority has the best browser compatibility

We're about to release a service that requires website owners to embed our javascript code on their site which will then serve the script from our server similar to Google Analytics. (yes I'm aware of ...
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508 views

What is the impact of certificate validation level (or class) on deployed web applications?

Certificates can have a class level (or validation level). What is the impact of these levels on deployed web applications? More specifically: Is the certificate level included in the certificate ...
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249 views

Cellphones IMEI public exposed?

Currently I'm in the middle of a developement process, and I have some security questions for you. I have a webservice, asp.net which is configured to run over https. The first authentication step for ...
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1k views

Which extensions to use for a S/MIME certificate?

Analogously to the SSL server certificate question, which extensions should I use for S/MIME, and should the CA be restricted somehow as well? (I'm using openssl, which at the moment creates CA and ...
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Extensions for SSL server certificate

I have some question about the X.509 v3 extensions. What extensions should appear in a proper certificate for a SSL server ?
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71 views

Standards for CA cert revocation and time-constrained cryptographic algorithm parameters

I'm working on software that will be in use for foreseeable future (15 years+) that will need to validate XAdES-A signatures (long term archival, similar to PAdES-A, but for XML). That means, it will ...
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2answers
491 views

Is it possible to modify a CA without having to reissue all of the derived certificates?

Background: I have my own authoritative certificate that I generated myself for signing certificates for services my friends and I use, including web server, ircd, etc. It's convenient because I ...
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571 views

Clients trust my custom CA

I'm sorry if this is a dumb question. I'm new to all this. I have a large number of users. I need to be able to generate SSL certs for various internal domain names. All of these certs need to be ...
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693 views

X.509 algorithm identifier parameters vs. extension values

From the X.509 specs: AlgorithmIdentifier ::= SEQUENCE { algorithm OBJECT IDENTIFIER, parameters ANY DEFINED BY algorithm OPTIONAL } ...
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104 views

Are there any public examples of an encrypted attribute in a Verisign-issued certificate?

This Credentica- UProve paper describes how Verisign issues (or did issue in the past) certs with encrypted attributes: "VeriSign issues certificates that contain encrypted attributes that can be ...
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93 views

Using SSL Certification in Multiple Locations

I have some issues with respect to using SSL Certificates. I have a website hosted in UK and I also have an organisation in South Africa hosting my company application online for web access. The ...
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1answer
632 views

Would introducing client certificates for a mobile app improve security?

I have developed a REST API which has been configured to only operate over HTTPS. The sole purpose of this API (at least for the moment) is to operate as the backend entry point for a mobile ...
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1answer
2k views

AIA/CRL locations for Offline Root

I've read the answer to the following "Checklist on building an Offline Root & Intermediate Certificate Authority (CA)" and I have one questions based on the system I am trying building It's an ...
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705 views

How to create an Apple Installer Package Signing Certificate

How can we create a certificate with the following Extended Key Usage extension using OpenSSL? Extended Key Usage extension, critical, with a purpose containing Developer ID Installer Package Code ...
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1answer
247 views

How secure is a https website? [duplicate]

Possible Duplicate: Does an established ssl connection mean a line is really secure When I visit a website -- say, https://ebanking.pick-your-bank.com -- my browser (fully patched version ...
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1answer
266 views

google certificates correct CA [closed]

I view certificates of https://www.google.com.ua/ So I thought, when requesting via cURL, if I point by CURLOPT_CAINFO to those certificates (GeoTrust Global CA and Google Internet Authority G2 in ...
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165 views

How does my antivirus determine which CTL is used?

I have imported a trusted root certificate into the Windows local machine list. This works fine with my signed certificates, unless my AV (Bitdefender Antivirus Plus 2012) is set to "scan SSL", in ...
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What is the meaning of http://uri.etsi.org/TrstSvc/eSigDir-1999-93-EC-TrustedList/SvcInfoExt/RootCA-QC from ETSI TS 102 231 V3.1.2

From Technical Spec http://uri.etsi.org/TrstSvc/eSigDir-1999-93-EC-TrustedList/SvcInfoExt/RootCA-QC a Root Certification Authority from which a certification path can be established down to ...
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I had SSL certificate on my site but still it has been hacked…how to prevent this from happening?

I used SSL certificate on my site but still it has been hacked. How do I prevent this from happening? Do SSL certificate come with a waranty which would compensate me because my site was hacked?
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Two-factor authentication w/certificate and username & password?

Example scenario: ActiveSync Authentication method: certificate-based authentication AND Active Directory domain username-password Encrypted on device: public & private key AD username ...
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580 views

Self signed certificates for https

Where I work, currently for internal sites, self signed certificates are being used. In Firefox, the info regarding the certificate are displayed: site domain: xxx.com Owner: Site doesn't supply ...
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3k views

What is an intermediate certificate authority?

What is meant by an "intermediate certificate authority?"
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240 views

When you buy a certificate, does the certificate authority have (a copy of) the private key?

I always assumed that the process for getting a (trusted, not self-signed) certificate was more or less like this: You generate a public and private key pair From this key pair you generate a ...
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745 views

Client Certificate in SSL HandShake insecure?

Imagine we have an application which is trying to establish a secure connection to a server by using SSL. Now we want the user to authenticate himself with a client certificate which he stores in an ...
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2answers
192 views

Are Windows Updates susceptible to tampering, eg. using a MiTM attack.

My real question is how are patches and updates authenticated in general. But for example how does windows know a windows update is really a windows update, does it just trust the URL or is there some ...
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1answer
729 views

Purpose of certificates signed and trusted by CA

Another newbie question but I just don't get the purpose of certificates signed and trusted by CA. We already have public/private keys, hash functions to sign/encrypt messages so why do we need ...
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599 views

How realistic and possible is this sort of attack

I scanned a host with Nessus, in order to do a vulnerability Assessment, and one of the findings looked really odd to me. Nessus rated this finding's risk as Medium. The finding was, that a service ...
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179 views

SSL Certificate Signing by a CA

Per my understanding about SSL's, a user has to send his CSR to a CA (Verisign) to get it signed, and Verisign will send the sign X.509 certificate in return. What I don't understand is what, ...
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112 views

Why does the RFC 5280 dictate the CAs not to issue certificates with negative serial numbers?

I have tried to issue a certificate beginning with 8 to F but I have found it is impossible, mostly due to the RFC: The serial number MUST be a positive integer assigned by the CA to each ...
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491 views

Change 'Key Usage' of a certificate

Is it possible to change the 'Key Usage' property of an existing ssl certificate of a web site? Our goal is to host a web service so that a third party can integrate with our solution, and their ...
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99 views

Is it a good idea to generate certificate-specific CRLs? What is this technique called?

Suppose I create 3 certificates with the following CRLs Cert1 http://crl.server.com/batch1/root1.crl Cert2 http://crl.server.com/batch2/root2.crl Cert3 ...
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1answer
436 views

exponent value in certificates

I have seen that in gmail, there are 3 certificates in hierarchy. I noticed that all the certificates have the same exponent(65537 with 24bits). Why is the exponent value same for all certificates and ...
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Need an overview of web service / web site security world, where do I start? [duplicate]

Possible Duplicate: Resources to learn about security I'd like to get a good understanding of modern issues in web security and get insight into what it takes to keep your sites and ...
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Protecting against SSL Strip [duplicate]

I've read you can attack connections using tools like sslstrip, if you are on the same network. So what ensures that our SSL connections remain safe? Does it depend on the cert strength? Do you ...
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x.509 CRLs: next update?

An X.509 certificate revocation list contains a field specifying when the next such list is expected to be issued. I'm trying to figure out the importance of this field...I know that sometimes ...
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2answers
156 views

In practice, does crypto software accept a *.com or or even a *. certificate?

Assuming this will be done with your own PKI, and not a public trusted CA. Considering that *.sub.domain.com is valid, and so is *.domain.com is valid, is it technically possible to issue *.com and ...
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Secure communication between C# client and Java server, using certificates

I want to secure communication between simple C# WPF client and Java server. Now i have already implemented raw sockets communication, and my security is based on: server send RSA public key to ...
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115 views

Risk in buying SSL cert from non well-know party

Let say I knew a guy is selling SSL cert in a very cheap price, assume they will generate a real and valid cert for me, since I need to submit my CSR to them and they pass to th CA, are there any ...
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1answer
53 views

Public keys without the certificates

There are two clients and a server. Each client generates an RSA key pair and uploads public key to the server. The server associates the public key with the user identifier that is specified during ...
3
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1answer
113 views

Clarification on Digital Certificates

I used the makecert tool to create: self-signed certificate client certificate These are the commands I used: makecert -n "CN=MatthewCA" -r -sv MatthewCA.pvk MatthewCA.cer **for self signed ...
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215 views

What are those nul bytes doing in Certificate Subject CN?

While doing some research with SSL certificates, I found some weird certificates containing nul bytes in their Subject field. One example is www.refah - bank.ir (did the Iranian government fake this ...
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2k views

Enhanced Key Usage vs. Extended Key Usage

I've seen both the terms Enhanced Key Usage and Extended Key Usage, and both were abbreviated as EKU. Do both refer to the same extension or property?
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662 views

What are the Netscape Cert Type attributes? Why/when are they needed?

What are the Netscape Cert Type attributes in a X.509 Certificate and how are they different with the X509v3 extensions? Example: There is the Client/Server Extended Key Usage (X.509) but there is ...