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 ...
6
votes
1answer
59 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
votes
1answer
92 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 ...
3
votes
3answers
76 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 ...
-1
votes
0answers
18 views
Digital signatures. Ways of implementation [closed]
I have been given an assignment with the following title: "Digital signatures. Ways of implementation", I am also supposed to create a small application illustrating the concept.
While I've been ...
6
votes
0answers
195 views
Web Authentication using PKI Certs [migrated]
I understand PKI reasonably well from a conceptual point of view - i.e. private keys/public keys - the math behind them, use of hash & encryption to sign a certificate, Digital Signing of ...
2
votes
2answers
45 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 ...
-1
votes
0answers
29 views
Why is my email address removed at the end of my matching public key file? [migrated]
I tried ssh-ing to a server that uses RSA verification. I was already able to ssh to this server months back but I find out that I can't do so today.
I investigated the keys in my computer. I emailed ...
3
votes
1answer
67 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 ...
2
votes
1answer
54 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 ...
-1
votes
0answers
60 views
What are my options in deploying an authentication certificate to iPhones and Android devices? [closed]
I need to deploy certificates to iPhone and Android devices for the purpose of Activesync and Egnnite (like Dropbox) web authentication.
Even though most access is over HTTPs via the browser, the ...
4
votes
1answer
53 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.
...
2
votes
0answers
46 views
Validate XML-DSig by DVCS
Is it possible to validate an XML message (with XML-DSig or XAdES signature) by a Data Validation and Certification Server (RFC 3029)? Should it understand XML signatures or not? Could it parse XML? ...
3
votes
1answer
63 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 ...
3
votes
2answers
108 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 ...
5
votes
5answers
195 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 ...
6
votes
2answers
243 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
60 views
Clarification on Digital Certificates
I used the makecert tool to create:
self-signed certificate
client certificate
These are the commands I used:
makecert -n "CN=MatthewCA" -r -sv MatthewCA.pvk MatthewCA.cer **for self signed ...
1
vote
1answer
25 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 ...
3
votes
1answer
196 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 ...
10
votes
2answers
188 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 ...
3
votes
2answers
149 views
BOTs C&C channels
Can someone please explain the C&C for bots ?
im reading a paper about Android bot , and its explaining something called URL flux
as method of C&C . however i couldn't really get it , so ...
1
vote
1answer
218 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 ...
5
votes
2answers
180 views
SSH password vs. key authentication
I've usually been told that public key authentication is strongly preferred over password authentication for SSH. However our previous admin was against public keys and only issued passwords and took ...
1
vote
1answer
81 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 ...
1
vote
1answer
84 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
186 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 ...
1
vote
1answer
122 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
28 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 ...
3
votes
1answer
171 views
Why do PGP master keys only have a single subkey, and tie certification with signing by default?
After learning more about PGP subkeys and how to split apart the roles of (S)igning, (E)ncryption, (A)uthentication and (C)ertification, I discovered that in most cases(?) a default master key has a ...
0
votes
1answer
125 views
How to test for OCSP
I have to test OCSP feature on a SSL server. Since it is a pretty standard feature now, I was looking around for tips on test plans / setting up OCSP responder etc. I have not found anything so far. ...
3
votes
2answers
109 views
Why are SSL certificates valid only from a certain date?
Each SSL certificate is valid starting from a specific date and up to the expiration date.
What's the point in that "valid from" date? Why do we want a certificate to only be valid after a specific ...
4
votes
2answers
99 views
Anything to do about old gpg keys?
Quite A few years ago (in middle school) I created some gpg keys, published them to a keyserver, etc. because I was l33test kid on the block. Now I have gone through a few new computers and OS's, ...
0
votes
1answer
156 views
Can I ensure that a public key derived from a private key is unique?
In asymmetric cryptography, is it possible to ensure that public key derived from a given private key is unique, no matter the algorithm?
1
vote
1answer
68 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 ...
0
votes
1answer
127 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 ...
1
vote
1answer
216 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 ...
3
votes
1answer
164 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
votes
1answer
337 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?
41
votes
10answers
3k 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 ...
4
votes
1answer
189 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
173 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.
4
votes
1answer
146 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
142 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
115 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 ...
4
votes
1answer
430 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 ...
2
votes
2answers
205 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 ...
11
votes
4answers
3k 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
90 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 ...
2
votes
2answers
259 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
115 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 ...
