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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11
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5answers
8k 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 ...
9
votes
2answers
2k 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?
3
votes
1answer
234 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 ...
11
votes
2answers
2k 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 ...
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 ...
5
votes
1answer
17k 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? ...
1
vote
1answer
305 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 ...
1
vote
1answer
2k 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 ...
1
vote
1answer
527 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
votes
1answer
6k 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
votes
1answer
3k 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 ...
12
votes
1answer
6k 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 ...
1
vote
1answer
679 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 ...
1
vote
1answer
812 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
1k views

distribution mechanisms for CRLs

From the X.509 RFC: DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, reasons [1] ReasonFlags OPTIONAL, cRLIssuer ...
6
votes
2answers
1k views

ASN.1: ENUMERATED vs INTEGER

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

What audit procedures are applied to ENotaries and to the software they use?

From a theoretical standpoint, the very notion of an electronic notary - ENotary implies a host of problems related to biometrics, signature revocation, timestamping, keeping a reliable electronic ...
1
vote
1answer
2k views

What key sizes are allowed within TLS if the DHE_RSA is the only key exchange allowed?

Can I make assumptions about minimum and maximum key sizes if all I know about a TLS server is the fact that it uses DHE_RSA for key exchange? Can the server be configured to use weak key sizes for ...
17
votes
4answers
21k views

How are Chrome and Firefox validating SSL Certificates?

How are Chrome and Firefox validating SSL Certificates? Are they requesting data from an SSL certification website, like GeoTrust, to validate the certificate received from the web server?
5
votes
1answer
6k views

What is the difference between RSA1 & RSA in regards to SSH? Also when is the fingerprint & random art used?

I have searched this site for RSA1 with no results. From multiple google searches I have understood that RSA1 was used in SSH1 (which isn't recommended). However if its a single algorithm why are ...
73
votes
10answers
18k views

Why do we not trust an SSL certificate that expired recently?

Every SSL certificate has an expiration date. Now suppose some site's certificate expired an hour ago or a day ago. All the software by default will either just refuse to connect to the site or issue ...
-2
votes
1answer
1k views

GPG advantages / disadvantages, is it useful or secure? [closed]

I thinking about GPG, is very widely used, but is secure? Why and where we using GPG? I found an article from 2002, but is very old.
2
votes
1answer
4k views

What Enhanced Key Usages are required for PKI infrastructure tasks? (OIDs for OSPF and CRL signing, etc)

I'm building a constrained PKI that specifies EKUs for the the entire hierarchy and want to document the OIDs required for PKI tree maintenance tasks. I understand that clients may not validate the ...
0
votes
3answers
282 views

Make the public key unrecoverable given the private key

OpenSSL seems to bundle the private key together with the public key when it produces .pem files. Is there a way to prevent this from happening; i.e. prevent OpenSSL from creating a .pem private key ...
1
vote
3answers
508 views

RSS Feeds: restrict access

"We are a bunch of journalists and we share much of the information via e-mails. This has become tedious now. Hence we found out a way to share, by just having to share our private blog posts via ...
6
votes
4answers
3k views

Is it possible to create a self signed certificate authority?

Would it be possible to create a legitimate certificate with the CA bit set? I dont have a usecase associated with this, I'm merely curious. To explain my question : Suppose I sign a public ...
3
votes
1answer
669 views

FIPS 140-1 and FIPS 140-2

I tried googling for this info but it's not easily available because FIPS 140-1 is now really old. Does FIPS 140-2 automatically cover FIPS 140-1 - i.e. if a device (in my case an HSM - Hardware ...
64
votes
4answers
54k views

What is the difference between an x.509 “client certificate” and a normal SSL certificate?

I am setting up a web service through which my company will talk to a number of business customers' services. We will be exchanging information using SOAP. I would like to handle authentication with ...
4
votes
3answers
3k views

Is a 512 bit RSA key secure when used temporary?

Is a 512 bit RSA key secure when a new key gets generated and used approximately once a week? The key is only used for signing messages, not for encrypting sensitive data. This is for a system where ...
6
votes
1answer
9k views

What damage could be done if a malicious certificate had an identical “Subject Key Identifier”?

I'm looking at the the Subject Key Identifier attribute of a CA certificate and am trying to understand the role it plays in validation and infer how validating client software could get it wrong. ...
5
votes
2answers
6k views

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 ?
3
votes
1answer
2k views

What should a CRL file name look like when “new” and “delta” CRLs are generated?

I suspect my Windows 20012 Certificate Server CRL revocation configuration is incorrect every time I generate a new CRL or a new Delta, only a maximum of 3 files are generated. When I created the ...
3
votes
1answer
203 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 ...
2
votes
3answers
2k views

What is the most secure way to do OCSP signing without creating validation loops?

I'd like to enable the most secure OCSP validation that Windows 2008 SP1 and newer support. Based on the following information, am I required to implement id-pkix-ocsp-nocheck on my OCSP ...
0
votes
1answer
674 views

How do I constrain Windows Smartcards for AD Authentication so that “anyExtendedKeyUsage” is not implied?

This document describes how there are 3 ways to constrain a SmartCard certificate The Enhanced Key Usage field defines one or more purposes for which the public key may be used. RFC 5280 states ...
20
votes
2answers
3k views

Which SSH security is stronger? 2 Factor or Public key

For SSH authentication, which is more secure? 2 Factor Authentication using a USB token/Google Authenticator(time based) OR Public/private key with password Or could they be both used at the same ...
4
votes
4answers
2k views

Why would someone want to encrypt RSS feeds?

I heard the idea of encrypting the RSS feeds using public key encryption system from someone and since then I am intrigued by the idea. But then I started to wonder what would be the basic need for ...
3
votes
2answers
3k views

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 ...
8
votes
2answers
1k views

X.509 certificate policies question

I asked another question about certificate policy mappings. This is a different issue. This is about Certificate Policies. To quote from the X.509 RFC: In an end entity certificate, these ...
1
vote
4answers
3k views

Does a renewed certificate open old messages?

I have a digital certificate that I use to exchange messages with peers, my certificate expiration date is due next year, suppose I renew this certificate before it expires, will I be able to open the ...
5
votes
2answers
6k views

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 ...
6
votes
1answer
2k views

What OID Issuance Policies are appropriate for SmartCard and Browser Certificates?

I'm investigating issuance policies for SMIME and Browser certificates with different levels of assurance. For the purposes of S/MIME and Browser certificates, should I even use an assurance policy? ...
3
votes
2answers
181 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 ...
24
votes
3answers
1k views

A Different Approach to PKI

After yet another failure of the public key infrastructure, I was thinking about how broken the whole thing is. This business of undeniably associating an identity with a public key, and all the work ...
2
votes
2answers
2k views

Difference between Encryption and Verification certificate

What is the difference between the Encryption certificate and Verification certificate in Outlook? When exchanging certs, it just requires a digitally-signed message to be sent. It seems as though ...
4
votes
1answer
203 views

Share or not share public key for servers?

In order to encrypt communications from our (custom) client to our (custom) servers our current scheme is a bit like this: Client uses the bundled public key A to encrypt some random key material. ...
1
vote
2answers
2k views

Self-signed certificates usage for code signing purposes

if a self-signed certificate is trusted by the client's certificate store, then it should be fine to be used, since the client trusts the issuer of the certificate as it does any other trusted CA ...
3
votes
1answer
733 views

What are the best practices for RSA-based security?

I'm building a platform with a strong security. Security is based on encrypting data with AES-256 encryption. Yet the system needs to "share" these keys among the users and they need to be transferred ...
3
votes
2answers
2k views

What hardware technology (GPU, FPGA) is fastest at generating RSA keys?

I'm interested in generating RSA keys in rapid succession and am looking for the correct hardware to so. I think what I'm looking for is very similar to a brute force attack on RSA keys, but my ...
10
votes
3answers
7k views

What issues arise from sharing a SSL certificate's private key?

Scenario: I am hosting a website for a my client, who we'll call S. S owns the domain s.com and I own the servers that actually host the website. S now wants to enable SSL on their website. I have ...