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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3
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1answer
337 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 ...
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?
50
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10answers
7k 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 ...
7
votes
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 ...
-1
votes
1answer
631 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.
6
votes
1answer
2k 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
386 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
votes
3answers
175 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 ...
9
votes
1answer
4k views

How to set up OpenSSH to use x509 PKI for authentication?

I do not mean simply putting the public RSA key of a x.509 certificate into ~/.ssh/authorized_keys - I'm looking for a way to set up a ssh such that x.509 certificates signed by a pre-defined CA will ...
3
votes
2answers
617 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 ...
43
votes
4answers
28k views

What is certificate pinning?

I'm superficially familiar with SSL and what certs do. Recently I saw some discussion on cert pinning but there wasn't a definition. A DDG search didn't turn up anything useful. What is certificate ...
3
votes
1answer
277 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 ...
5
votes
2answers
404 views

How to implement a Web of Trust?

How to implement a Web of Trust, or something similar? Alice get a public and a private key from the RSA guy. Bob need to send to Alice a nuclear secret code (or his babysiter's phone number). Bob ...
1
vote
3answers
309 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 ...
4
votes
4answers
2k 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 ...
1
vote
1answer
727 views

How does a developer interact with Microsoft Certificate *Web Services*

Microsoft Certificate Web Services is a HTTPS web service (WS-Trust) that has no Kerberos dependency and can be used on a variety of devices. This is new in Windows 2008 and is separate from the ...
2
votes
2answers
806 views

Is the use of DSA keys a security risk?

According to the answers on this question the differences between RSA and DSA would seem to be trivial. However, according to this page DSA compromises your security if anyone is sniffing your ...
0
votes
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 ...
5
votes
1answer
3k 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. ...
3
votes
1answer
111 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 ...
3
votes
1answer
913 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 ...
2
votes
1answer
1k 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 ...
4
votes
2answers
3k 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 ?
4
votes
3answers
1k 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 ...
4
votes
4answers
1k 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 ...
4
votes
2answers
2k 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 ...
3
votes
1answer
1k 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? ...
24
votes
3answers
945 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
795 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 ...
1
vote
1answer
346 views

How do I verify, parse and process the results of the HTML5 keygen tag?

I'm investigating the HTML5 attribute Keygen and discovered that it sends this data on a Form POST to the server. Here is an example POST: ...
4
votes
1answer
146 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. ...
3
votes
1answer
395 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 ...
1
vote
2answers
797 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 ...
2
votes
3answers
2k views

Making a Windows cert say it's purpose is “Ensures the identity of a remote computer”

Maybe this is a superuser.com question, I don't know. Anyway, I want my cert to show up like this when I double click on it in Windows: If I just double click on a random cert I get this: The ...
3
votes
4answers
9k views

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 ...
17
votes
2answers
1k 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 ...
0
votes
4answers
1k 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 ...
4
votes
1answer
124 views

What physical, electronic, and software characteristics are important in a smart card?

I'm evaluating smart card readers to store a number of private keys, but don't know where to start. What criteria is important regarding smart cards and preventing the extraction or unauthorized used ...
2
votes
1answer
159 views

how does OpenSSL create X.509 certs from SPKACs?

The SPKAC ASN.1 description: PublicKeyAndChallenge ::= SEQUENCE { spki SubjectPublicKeyInfo, challenge IA5STRING } SignedPublicKeyAndChallenge ::= SEQUENCE { publicKeyAndChallenge ...
1
vote
1answer
220 views

spkac: what is the purpose of the challenge string?

The SPKAC ASN.1 description: PublicKeyAndChallenge ::= SEQUENCE { spki SubjectPublicKeyInfo, challenge IA5STRING } SignedPublicKeyAndChallenge ::= SEQUENCE { publicKeyAndChallenge ...
4
votes
2answers
752 views

What did the certificate authority do with my CSR?

I needed to reach a web service which is not mine. The IT department of that web service has asked me to send them a CSR (certificate signing request). Then, he will send me back a signed certificate ...
6
votes
3answers
2k 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 ...
3
votes
2answers
835 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 ...
1
vote
4answers
371 views

RSA and encrypted authentication

Symmetric algorithms such as AES provides modes such as GCM which can be used for authenticated encryption. Assuming that I'm using RSA instead of AES, does it still make sense to add authentication ...
2
votes
3answers
180 views

Given a large enough sampling of public keys could one begin to identify a private key?

For example, an ISP or government capable of tracking millions of keys being exchanged. Would that provide a sample large enough to be able to identify the private key on either end?
142
votes
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 ...
4
votes
4answers
297 views

Securely publishing GPG keys

This is probably a stupid question/vaguely defined, but I need to ask it anyway. I want to put a public key for mail exchange on my website, such that even very powerful adversary with power to ...
1
vote
1answer
287 views

signatureAlgorithm vs. tbsCertificate -> signature

From the X.509 RFC: Certificate ::= SEQUENCE { tbsCertificate TBSCertificate, signatureAlgorithm AlgorithmIdentifier, signature BIT STRING } TBSCertificate ::= ...
3
votes
1answer
159 views

Can we use a public key scheme for performing cryptographic commitment

Is it possible to use a public key scheme such as DSA as a commitment scheme? Are there any problems with doing this?
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votes
4answers
613 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 ...