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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2
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868 views

Key Exchange using PKI

I'm new to the field of cryptography and trying out a sample program to understand PKI key exchange mechanism. I tried creating a self signed certificate using openssl openssl req -x509 -nodes ...
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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 ...
5
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2answers
155 views

How can a certificate be valid in the Hybrid Model but not in the Chain Model?

All dates in European format! I am learning about validity models, but the solution for this assignment confuses me. Translation: The relevant data for the applicable certificates are shown ...
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7answers
11k views

How do certification authorities store their private root keys?

Knowledge of a CA private key would allow MitM attackers to transparently supplant any certificates signed by that private key. It would also allow cyber criminals to start forging their own trusted ...
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4answers
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how to import a private key in windows

Say I have an X.509 cert and a private key that corresponds to it. I can import X.509 certs easily enough into Windows but what about private keys? Is the only way I can do that by converting both ...
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1answer
292 views

generating RSA keys through the browser

HTML5 has the element that sends an SPKAC to the server (as I understand it). But how do you do it in IE? One CA's websites gives me the following prompt: This Web site is attempting to perform a ...
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1answer
1k views

Does Java's implementation of OCSP and CRL checking handle intermediate CAs?

I've read that Java provides OCSP and CRL checking for CertPaths via: Security.setProperty("ocsp.enable", "true"); System.setProperty("com.sun.security.enableCRLDP", "true"); Do these implementations ...
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1answer
287 views

signatureAlgorithm vs. tbsCertificate -> signature

From the X.509 RFC: Certificate ::= SEQUENCE { tbsCertificate TBSCertificate, signatureAlgorithm AlgorithmIdentifier, signature BIT STRING } TBSCertificate ::= ...
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2answers
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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 ...
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1answer
336 views

Internal CA for Digital Signature Solution - PKI Based

I'm trying to set up a digital signature solution which would work with a internal PKI. We have considered Microsoft Certificate Services, but we don't want to rule out any other option to set up a ...
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1answer
114 views

XER encoded X.509 certs [closed]

Would anyone happen to have an example of an XER encoded X.509 certificate so I can play around with it? Thanks!
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3answers
719 views

Public key Infrastructure

Here the MD5 hash is being encrypted with the private key of the sender. But I read in a paper that private key is only used for signing and not encrypting. Is the image wrong or can private key ...
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1answer
185 views

are organizations that receive certificates considered “end entities” in a PKI?

I am trying to understand the term end-entity. Does this term just mean anybody that plays a role in a PKI system that is not a CA? So if I request a certificate from A who is a CRL issuer for ...
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2answers
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Checking SSL\TLS servers for null encryption support

I have a web server supporting SSL 3 and TLS protocols , the following are the supported cipher suites. TLS_RSA_WITH_RC4_128_MD5 TLS_RSA_WITH_RC4_128_SHA TLS_RSA_WITH_3DES_EDE_CBC_SHA How can i ...
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2answers
130 views

Is there a reason to encrypt an encryption key with a certificate before storing it?

Suppose my .Net application which is installed in the client encrypts a data. I want to use a different key generated randomly for each client so each client doesn't know the key of the other. Someone ...
3
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1answer
503 views

Can you make a digital signature using the receiver's public key?

My question is, can you make a digital signature using the receiver's public key and then have the receiver verify the signature using his private key? I always thought that in order to create a ...
3
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3answers
314 views

Two-way secure communication using two pairs of public/private keys?

Let's say I want to create a protocol to securely communicate between two endpoints - each of the two endpoints know the other's public key and all data exchanged is encryted using one's public key ...
4
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2answers
3k views

Certificate Chain checking

I have a very specific question. A client verifies a sever by taking the certificate and checking specific values and that the digital signature of the intermediate CA is correct (According to the ...
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2answers
615 views

How to secure a truecrypt container allowing access with multiple SSH public keys?

I would like to create a TrueCrypt container which can be accessed by multiple people. The container itself can be stored anywhere, e.g. in a shared folder in Dropbox or Google Drive, ... I would ...
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3answers
912 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 ...
3
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2answers
468 views

How safe is a PGP private key that has “escaped”, but without its password?

Assuming your PGP private key is protected with a password, and it "escapes", but the password does not, how worried should you be? Obviously in the real world, you would immediately revoke the key ...
6
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1answer
139 views

public key distribution from a central server

I'm trying to code up a encrypted communication program. Originally I was thinking that I would use public key cryptography and then I would keep the public keys in a database where users could query ...
2
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1answer
926 views

Are very short messages secure using Public Key Encryption? [duplicate]

Say Alice publishes her public key and then disappears from public view. Bob then needs to send a message to her that's either "OK" or ":(" so he takes her public key, encrypts his message and then ...
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2answers
1k views

Are there really functioning quantum computers?

I saw this video on youtube on quantum computing. It says that a company called dwavesys has already made commercially available quantum computer. I checked on the website and it exists. I thought ...
2
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2answers
157 views

Verifying the authenticity of a public key without manual intervention?

In RSA encryption it is said that ensuring the authenticity of the public key can be as important as the protection of the private key. An effective way of doing this is to have key custodians ...
3
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1answer
152 views

Design of system based on HTTPS, Client Certificates and custom CA

I have the following system: 2 application servers. At the beginning is installed the first server and later is installed the second one. A client access from a browser to both servers Application ...
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4answers
612 views

Are there any hardware HSMs that can host/run custom applications using the HSM processor(s) within the hardened security boundary?

It seems that the majority of commercially available hardware HSMs are only designed to allow authenticated users to generate, store, and use cryptographic keys with various cryptographic algorithms ...
2
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1answer
70 views

Remote network security option

I'm a bit confused with some different network security techniques. Say we want a secure communication with a particular mail server in a remote company network. Reading and sending mails should be ...
4
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1answer
252 views

PKI integration in MAC OS

I have setup an ejbca pki and integrated certificates in MAC OS for S/MIME signing and encrypting. I have also set up a CRL distribution point and put the CRL online available on an HTTP server. ...
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3answers
2k 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 ...
5
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1answer
2k views

What is the difference between Key Escrow and a Recovery Agent?

From what I understand Key Escrow is where a copy of they key is stored in a safe place so they can be recovered later. But in the context of PKI, a Recovery Agent can also recover private keys. How ...
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5answers
3k views

A standard way to manually add a digital signature to a pdf file?

I've created a few certificates to use myself, but I find myself stumped when it comes to creating a certificate which contains a digital signature. First, how would I go about creating a standard ...
8
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2answers
843 views

Is ECDSA breakable by quantum computers?

Is ECDSA secure from quantum computers? Will quantum computers be able to calculate it's private keys from the knowledge of the public key once there are working quantum computers?
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3answers
8k 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?
3
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1answer
225 views

Remote System Administration of an Encryption-Switch-Encrypted Infrastructure

I can't seem to find a decent explanation anywhere of the practicalities of remote system administration (e.g. SSH) of an encryption-switch-encrypted SAN-stored infrastructure. The environment will ...
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2answers
922 views

What does having an internal two-tier PKI protect against?

There are a lot of Best Practice documents that recommend having an offline Root CA and an Enterprise Subordinate CA that is signed by the root, for an internal Microsoft AD Certificate Services ...
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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 ...
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1answer
8k views

What is updated with “Update Root Certificates” enabled? What is the equivalent in Windows 2008R2?

What root certificates are/are not updated when the following checkbox is checked? Additional questions If I manually remove a root certificate, will this service replace that very certificate? ...
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1answer
170 views

How to have Thunderbird include a root certificate?

An eMail signed via S/MIME also contains the X.509 certificate chain containing the public key in order to directly verify the signature (assuming its issuing CA is deemed trustworthy). The chain does ...
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1answer
1k views

Can I use any ssl certificate to sign and encrypt AS2 message?

I'm absolutely new to this topic of ssl certificates, so please be patient with me. My task is to install an AS2 communication with some business partner. Therefore we need message signing and ...
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1answer
216 views

x509: must the signature algorithm and public key algorithm match?

I'm having trouble getting Firefox to send an encrypted message using a certificate, and I've found that the only difference between this one and others that work fine are that this one has a DSA ...
4
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1answer
699 views

Why is ECC more vulnerable than RSA in a post-quantum world?

Forgive me if this should be in the crypto sub, but sometimes the answers there are very mathematical and I would rather have an answer which is a bit lighter on the math but still strong on the tech ...
3
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1answer
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?
7
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1answer
1k views

Why do X.509 certificates have “Key Usage” attribute?

I can find their values and all details in the RFC, but I cannot find why it was decided to have this attribute in certificates, instead of leaving them to be multipurposes. Is there a reasoning ...
6
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1answer
1k views

Which properties of a X.509 certificate should be critical and which not?

RFC5280's section 4.2 states Each extension in a certificate is designated as either critical or non-critical. A certificate-using system MUST reject the certificate if it encounters ...
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1answer
385 views

How to troubleshoot why Thunderbird rejects a PKCS#12 certificate with “Could not verify this certificate for unknown reasons”?

After playing around a bit with openssl, I created a PKCS12 certificate which imports flawlessly in Firefox while Thunderbird "Could not verify this certificate for unknown reasons". Talk about a ...
0
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1answer
445 views

Behavior when validating an expired certificate chain

I have the following situation: A server certificate (CServ) is signed by self-signed certificate (C0) A client certificate (CCli) is signed by CServ Client's trust-store contains C0, so the client ...
2
votes
2answers
500 views

distribution mechanisms for CRLs

From the X.509 RFC: DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, reasons [1] ReasonFlags OPTIONAL, cRLIssuer ...
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2answers
488 views

ASN.1: ENUMERATED vs INTEGER

From the X.509 specs: CRLReason ::= ENUMERATED { unspecified (0), keyCompromise (1), cACompromise (2), affiliationChanged (3), ...