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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X509Certificate - How to set validation Policies?

I have an X509Certificate (say Certificate-A) for signing purpose. While validating this certificate, I have to check its path with Intermediate & Root certificate which I have implemented fully. ...
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1answer
22 views

list of PKCS7 certificate file extensions

RSA (the company) devises and publishes the public key cryptography standards. In those standards PKCS #7 is a standard which defines how to encrypt and sign messages using PKI. PKCS#7 defines a ...
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43 views

Using client certificates for website authentication

I was wondering if there currently exists a Content Management System that supports PKI and client certificates for website authentication instead of username/passwords. If not, what's a good place to ...
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1answer
201 views

Heartbleed - is this scenario possible? how bad would it be?

Let's make the following assumptions: A trusted root certificate was being served with a vulnerable version of OpenSSL. Prior to public disclosure, a malicious entity was aware of and exploited the ...
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2answers
77 views

Where to find or purchase non-SSL certificates

I hope this is the right stackexchange - if not, please advise. As to the actual question: have a system we've developed that makes heavy use of asymmetric cryptography in various different ways ...
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1answer
81 views

Trusted Certificate Authorities - how do they work?

microsoft.com for example can use a Verisign Certificate for their domain. What are the chances that an attacker could ask verisign for a m1crosoft.com domain and get approved? It is very simillar, ...
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133 views

Can a smart card with PKI certificate be used to protect a document?

I want to use a smart card (or USB cryptotoken) with a PKI certificate for manual authorisation. Is this possible? I want to put a file (e.g. a word file or even a simple text file) into a smart ...
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1answer
178 views

WebRTC P2P SSL - Where are the keys generated?

My understanding is that with the WebRTC peer-to-peer data API, communications between peers are encrypted via a modified form of SSL. Where are the keys for the peer-to-peer SSL connection generated, ...
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4answers
71 views

When should I use symmetric encryption instead of RSA?

I'm currently using GPG RSA keys to encrypt binary files. Many people recommend using symmetric keys to encrypt large files, and then encrypt the symmetric key with a public key. At what file size ...
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How dangerous might be publishing a public key?

Maybe this question sounds obvious, but I wonder how dangerous might be publishing a public key for an asymmetric encryption system? I know public keys are meant for encrypting messages by anyone ...
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1answer
50 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 ...
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1answer
49 views

Possible to Derive Private Key from Public Key Given Enough Computing Power? [closed]

Is it possible via brute force to derive a private key from a public key (such as a website's SSL certificate)? If so, how much computing power would you need to make it feasible, compared to say, ...
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68 views

SSL/TLS : Authentication mechanism

I have these doubts regarding authentication in SSL/TLS : Will there be an authentication involved for all SSL connections ? For eg. when I browse the internet, using the most up-to-date browser, ...
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2answers
132 views

How to maintain security and trust with a PGP keypair for a team or group of people?

I've seen many instances where a company or organization generates and uses a PGP keypair for a team or group of people. Most likely they all have a copy of the private and public keys on their ...
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2answers
38 views

Achieving PFS with public key cryptography

I'm seeking to understand how Perfect Forward Secrecy (PFS) works for non SSL applications. More specifically, I'm interested in how Moxie Marlinspike accomplishes this in TextSecure and other ...
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3answers
167 views

Why do you need to encrypt symmetric key?

I'm reading this pki article and as you can see near the bottom, the quick animation and description: The sending computer encrypts the document with a symmetric key, then encrypts the symmetric ...
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3answers
42 views

Detect message tampering without shared key and without certificate authority

Is it possible to detect if a message has been tampered with, without using MAC (i.e. shared key) and without using a "trusted" third party (i.e. certificate authority)? I'm pretty sure it's not, but ...
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1answer
15 views

OID for creation date/time (X509 certifcate field)

X509 certificates used in PKI{X} have notBefore and notAfter dates. I'd like to stamp a certifcate with a creation stamp, and the stamp is distinct from notBefore and notAfter. Is there an OID for a ...
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2answers
87 views

Digital Signatures of XML, PDF and Office Documents on every platform

I'm trying to develop a website that performs digital signatures on client-side and then sent the signed document to the server-side. I want to do the signatures on client, due to the fact of not ...
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3answers
125 views

Is it ok to send user's private key away, even if protected with a SSL channel?

I'm developing a webserver that performs digital signatures of (xml, pdf and office) documents and then validates those signatures. My idea is: an user puts its SmartCard and through a PIN, he gets ...
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4answers
40 views

Is it ok to send user's private key away, even if protected with a SSL channel? [duplicate]

I'm developing a webserver that performs digital signatures of (xml, pdf and office) documents and then validates those signatures. My idea is: an user puts its SmartCard and through a PIN, he gets ...
1
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1answer
75 views

Is there any way to restrict multiple access to my server at the same time using one client certificate?

My Server is Windows 2008. Mr. X is accessing my web server using Mr. X's certificate. In that time, an outsider is also trying to access my server using Mr. X's certificate (somehow he got it). Is ...
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2answers
86 views

Protecting against/detecting a specific Man in the Middle attack

I'm working on a specific (hypothetical) situation, where I have two client machines attempting to perform a public key exchange, via a server. There's no possibility for a direct connection between ...
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3answers
98 views

How encryption/decryption works when one generate random key?

I am new to this and want to ask a basic question.Suppose I used my password (say "ABC123") to generate a key using PBKDF2 algorithm (or any such algorithm).For encrypting a file I'll input my ...
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0answers
55 views

Import securely RSA private key through PKCS#11

I have a cryptographic device that supports the following mechanisms: How I could securely import RSA private key into it? Because there is no support for wrap/unwrap using symmetric key is there ...
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0answers
32 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 ...
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1answer
28 views

In a 3 tier (or more) PKI, is it permissible that a Name Constraint only be defined on the middle tier?

I'm working with an Issuing CA that doesn't support name constraints that are defined at a higher level. Assuming that it issues certificates that are compliant with the Name Constraints that are ...
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1answer
54 views

Internal code-signing certificate on Windows

I'm looking to improve defense-in-depth on a system, primarily by closing some holes in injected DLLs. Certain applications installed on the system cause helper DLLs (e.g. shell extensions, BHOs, ...
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3answers
135 views

Why can't someone break email or https encryption by somehow getting access to the encryption key?

To repeat, "Why can't someone break email or https encryption by somehow getting access to the encryption key?" In other words, why can't someone intercept the key, or the algorithm to create the ...
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235 views

Why are private certificates not trusted?

When we go to websites that have generated certificates themselves you see this red screen that says do not go there!: However when it is trusted by some companies it's all good. So I have a couple ...
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3answers
91 views

Using public/private key without signed certificate

I am working on a java program and I am now working on its network security. I want to use a secure connection since it transfers a lot of sensitive information. On all security guides it is mentioned ...
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1answer
73 views

Public Key Cryptography : Key length

While symm. crypt. has around 256 bits of a key, why does public key crypt have a key that is much longer (1000's) ???
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3answers
241 views

Does checking the fingerprint of a self signed certificate improve security?

I am currently developing a component for an application that does TCP communication with a device inside a local area network. I use TLS to provide data encryption, integration and authorisation. ...
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3answers
222 views

Managing and storing lots of SSH keys in the cloud

I have a pool of cloud servers (~50) that need to talk to many other remote cloud servers (~4000) using SSH. Each remote server has its own SSH key, so we need a place to store all of these remote ...
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1answer
71 views

Protecting data on an embedded device

I am to release a system-on-chip device that, during its lifetime, will come to store sensitive data. I want to make that data hard to extract or duplicate. Encrypting is good for dealing with MiTM, ...
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2answers
424 views

Cryptography behind chip based credit cards (smart cards)?

Why are chips safer than magnetic stripes? The answers to the above question explain that the chip based cards can not be cloned as the "secret number" is embedded in the chip and protected by the ...
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3answers
316 views

How are private keys handled in an enterprise?

We would like to start using digital signatures and possibly encryption for e-mails in our company. My knowledge of public-key cryptography is entirely theoretical with no practical experience. In ...
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1answer
168 views

Root certifcate key usage (non-self-signed end entity)

This discussion does not include self-signed end entity certificates for hosts like web servers and mail servers. OpenSSL's default configuration for a CA certificate has the following keyUsage: ...
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1answer
160 views

How to process or manage Key-Encryption-Key using HSM?

Let's consider two Encryption keys: 1.Data-Encryption-Key(DEK) 2.Key-Encryption-Key(KEK) KEK will be securely stored in HSM, which will be encrypted using master key. Data Encryption Key will be ...
2
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1answer
81 views

How can a trusted intranet certificate be issued if they are being phased out?

I've just seen this article regarding the phasing out of intranet names on SSL certificates. However, CAs such as this one claim to still issue them and it will be "Trusted by all popular browsers" ...
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200 views

Which digest algorithm to use with creating a public/private key pair

I'm generating a Public/Private key pair in PHP with the following: <?php $config = array( "digest_alg" => "sha512", "private_key_bits" => 4096, "private_key_type" => ...
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4answers
121 views

search CA for someone's public key

do CAs offer service wherein an application can request someone's public key? i am trying to do this but i am unsure if it is correct (suggestions of better ways to do it will be most appreciated): ...
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2answers
120 views

Nested encryption for multiple users

I've developed a web application (developed in .NET MVC 4) which have multiple users with personal login credentials. The web application holds a lot of content uploaded by the users. My client would ...
3
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1answer
83 views

Can we build a key exchange protocol without certificates?

Assume that the server and the client both has some secret key K. Is it possible to have a key exchange protocol with authentication between them such that MITM attack cannot hold and if the key is ...
4
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1answer
241 views

Who is this strangely named Certificate Authority?

I'm researching certificate authorities, and I just have no idea what to think of the CA named x00Ax00-x00Tx00rx00ux00sx00tx00 x00Gx00ex00sx00.x00 x00fx00xFCx00rx00 ...
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3answers
125 views

Governement like classified information system

I need to implement a classification system for my company, similar to the government's. I'm working for a company working with the government. The classification system in my country isn't public so ...
2
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1answer
71 views

What do people mean by “top-down manner” in X.509 certificates?

What do people mean by saying that X.509 certificates work in "top-down manner"? Do they say that because CAs can do cross certifications?
2
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1answer
95 views

Learning recommendation for Enterprise PKI design and management?

I'd like to learn the top-shelf methods for designing and managing a generic X509 certificate infrastructure. There's some books here and there, but I figured I'd ask if anyone here has any favorites. ...
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685 views

Why is a CA certificate required for EAP-TLS clients?

When setting up clients with WPA2 EAP-TLS, most clients (ie: my phone, my computer) require both a client public/private keypair (for obvious reasons) and a certificate authority certificate. It's ...
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5answers
253 views

Is asymmetric encryption vulnerable to man-in-the-middle attacks?

I'm looking for ways to send private messages over a public channel, and in doing this I stumbled in asymmetric encryption, which is just perfect for what I was looking for at first - A and B ...