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 ...
1
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2answers
153 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 ...
28
votes
4answers
13k 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 ...
5
votes
3answers
349 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 ...
2
votes
1answer
105 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.
...
4
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2answers
201 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 ?
2
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1answer
177 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
54 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 ...
1
vote
3answers
432 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
246 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 ...
11
votes
2answers
463 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
496 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
410 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 ...
3
votes
3answers
544 views
How is an X509 certificate signer verified?
Lets say I create a self-signed certificate A and use it to issue certificate B. I put certificate A in my trusted root authorities so that all certificates signed by it are accepted. My question is,
...
7
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2answers
281 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 ...
10
votes
4answers
1k views
Are there technical disadvantages in using free ssl certificates?
Note this question is related, except this one is about free SSL certs.
There are providers who are offering totally free entry-level SSL certs (like StartSSL). I was wondering if they are ...
7
votes
1answer
236 views
Why is there no Domain CA?
I was asked to deliver a signed SSL certificate for an IIS server for a client.
I have previously done this for the same client/domain before, so it start to seem like
an unnecessary expense to hold ...
11
votes
3answers
9k views
Expired SSL Certificate Implications
What are the security implications of an expired SSL certificate? For example if an SSL certificate from a trusted CA has expired will the communication channel continue to remain secure?
6
votes
3answers
188 views
Renew digital certificate
If I have deployed a digital certificate on a webserver and if it needs to be renewed then what steps do I need to follow? Will I need to generate a new longer public key private key pair? Why do ...
-1
votes
4answers
232 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 ...
3
votes
2answers
224 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 ...
8
votes
2answers
3k views
Checklist on building an Offline Root & Intermediate Certificate Authority (CA)
Microsoft allows a CA to use Cryptography Next Generation (CNG) and advises of incompatibility issues for clients that do not support this suite.
Here is an image of the default cryptography settings ...
2
votes
1answer
232 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
133 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
810 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 ...
1
vote
2answers
190 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
129 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
90 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
5answers
654 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 ...
1
vote
2answers
188 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
151 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 ...
2
votes
2answers
268 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 ...
4
votes
3answers
260 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
158 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 ...
2
votes
1answer
76 views
how does OpenSSL create X.509 certs from SPKACs?
The SPKAC ASN.1 description:
PublicKeyAndChallenge ::= SEQUENCE {
spki SubjectPublicKeyInfo,
challenge IA5STRING
}
SignedPublicKeyAndChallenge ::= SEQUENCE {
publicKeyAndChallenge ...
2
votes
3answers
188 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 ...
0
votes
0answers
81 views
What McEliece key size can provide standard security today? [closed]
i don't wanna use RSA because it will be plaintext very soon but we can't stop using internet to send private data.
Does McEliece cryptosystem provide security today ?
What McEliece key size is ...
3
votes
1answer
70 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 ...
1
vote
1answer
65 views
spkac: what is the purpose of the challenge string?
The SPKAC ASN.1 description:
PublicKeyAndChallenge ::= SEQUENCE {
spki SubjectPublicKeyInfo,
challenge IA5STRING
}
SignedPublicKeyAndChallenge ::= SEQUENCE {
publicKeyAndChallenge ...
117
votes
7answers
6k 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 ...
1
vote
4answers
166 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
141 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?
0
votes
0answers
31 views
Source(s) for getting listed vulnerabilities? [closed]
As I know cve.mitre.org, is one major source from which we can get to know all the listed vulnerabilities (new and old).
Are there any other such sites or databases available?
Also, if I want ...
1
vote
1answer
205 views
X.509 certificate policy mapping question
So I'm a little confused how X.509 certificate policy mappings work. So let's say the following depicts my cert chain:
root CA ---> intermediary CA ---> client cert
Would the root CA have a ...
5
votes
4answers
164 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 ...
8
votes
2answers
2k views
SSL Certificate revocation check
In the SSL protocol I don't see where the certificate is checked for revocation status.
https://developer.mozilla.org/en/Introduction_to_SSL
Is the Certificate Revocation and Status Checking not ...
16
votes
4answers
4k views
How does PGP differ from S/MIME?
Is S/MIME an abstracted system for general MIME type encryption, whereas PGP is more for email? Why would I want to choose one over the other, or can I use both at the same time?
1
vote
1answer
84 views
signatureAlgorithm vs. tbsCertificate -> signature
From the X.509 RFC:
Certificate ::= SEQUENCE {
tbsCertificate TBSCertificate,
signatureAlgorithm AlgorithmIdentifier,
signature BIT STRING }
TBSCertificate ::= ...
5
votes
2answers
110 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 ...
3
votes
1answer
96 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?
3
votes
3answers
171 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 ...
