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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7answers
12k 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
308 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
347 views

signatureAlgorithm vs. tbsCertificate -> signature

From the X.509 RFC: Certificate ::= SEQUENCE { tbsCertificate TBSCertificate, signatureAlgorithm AlgorithmIdentifier, signature BIT STRING } TBSCertificate ::= ...
3
votes
1answer
167 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?
4
votes
5answers
755 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 ...
-1
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1answer
120 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!
2
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3answers
819 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 ...
5
votes
2answers
160 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 ...
1
vote
1answer
107 views

How are root CAs for SSL distributed?

For internet explorer or whatever, I get it... It's in essence a sneakernet, you get them on the physical media from which you install your system and browser. But what about for firefox and chrome? ...
4
votes
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 ...
4
votes
3answers
4k views

How to distribute client certificates without exposing private key?

I'm desgining a B2B web service based on WCF. As the number of clients is relatively small and security is a priority, i have chosen to go with X509 client certificates for client authentication. I'm ...
2
votes
2answers
591 views

distribution mechanisms for CRLs

From the X.509 RFC: DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, reasons [1] ReasonFlags OPTIONAL, cRLIssuer ...
4
votes
1answer
268 views

where to download revoked certificates from

I don't want the certificate revocation lists - I want actual full on revoked certificates for test purposes. For example, Flame used a signed rogue cert and in 2001 someone posed as Microsoft and ...
2
votes
2answers
976 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 ...
25
votes
4answers
3k views

What alternatives are there to the existing Certificate Authority system for SSL?

Whilst the current CA system works very well for a lot of people, it does put a lot of power into individual CAs' hands, and makes a CA hack potentially devastating for customers and business. What ...
-3
votes
1answer
115 views

How to distribute public keys in the network without losing its credibility? [closed]

How to solve the key distribution encrypted with the public key? How to make public key authentication? How to distribute public keys in the network without losing its credibility?
1
vote
2answers
159 views

Certificate Security in intranet Environment?

We have this topology in our company : A new rule says that each document being sent by outlook should be encrypted. we decided using PGP. We already have a certificate ( self signed). the ...
4
votes
1answer
386 views

Is OpenPGP encryption a valid replacement for SSL when passing messages?

I am writing an application that occasionally needs to transmit larger messages to other servers on the internet without allowing people to snoop on the traffic. The normal way to handle this is to ...
11
votes
2answers
1k views

Is it okay to widely share the RSA key fingerprint for a host?

When you ssh into a remote box for the first time or if the remote host's key fingerprint has changed (from what's stored in your known_hosts file) you get a warning and you are shown the fingerprint ...
5
votes
1answer
408 views

Which attributes of a X509v3 certificate are never really used?

Are there any extensions/extended key usage attributes of a X.509Certificate that are rarely or never used in practice? Either due to never being part of an issued certificate or because they are ...
10
votes
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 ...
3
votes
1answer
1k views

What are the Netscape Cert Type attributes? Why/when are they needed?

What are the Netscape Cert Type attributes in a X.509 Certificate and how are they different with the X509v3 extensions? Example: There is the Client/Server Extended Key Usage (X.509) but there is ...
1
vote
1answer
560 views

Why does the OpenSSH client on Mac OS X silently launch an ssh-agent for the user?

I'm confused by the difference in behavior of ssh clients I'm seeing on two different hosts. Just to be clear, this is the scenario: "macbox" OS X using OpenSSH_5.2p1 ssh client "sunbox" Solaris 10 ...
2
votes
2answers
808 views

Revoked certificate validation using past times

I'm working on XAdES implementation for Java, as such I require cryptographic implementation to be able to verify certificates in the past. Unfortunately I have problems verifying revoked ...
3
votes
3answers
121 views

Can the root of a system access to unencrypted data when using a double tunnel?

I connect to a DMZ gateway system (B) which is not secured. From this machine (B) I can connect to the final destination (C). A-->B-->C I created a ssh tunnel from A to B and forwarding the port 22 ...
1
vote
0answers
203 views

Verifying Authenticode signed executables and DLLs using OpenSSL API [closed]

I have installed openssl and now the rsa_test.c is running fine. What I want to do is: Open any exe or dll digital certificate. Extract the Thumbprint and PublicKey. The public key contains the ...
6
votes
2answers
582 views

ASN.1: ENUMERATED vs INTEGER

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

Which .CER file format is more secure for purposes of an AIA record?

What file format is most appropriate or secure for the AIA record in a PKI certificate? The options I'm aware of are: DER encoded binary X.509 (.cer) Base-64 encoded X.509 (.cer) I also have the ...
5
votes
1answer
246 views

security issue on storing keys and certificate on token

I'm creating a sample USB token with Atmega64. As I have to store both the public and private key and the certificate on my token is there any important security issue that I should worry about, ...
3
votes
2answers
491 views

Distributed XAdES-X and XAdES-A signatures over multiple documents

As the standard is not completely clear in this matter, I'm trying to found out if the XAdES standard (ETSI TS 101 903 v1.4.2) describes distributed case in which the SigAndRefsTimeStamp element or ...
1
vote
1answer
138 views

What keys are involved in an X.509 certificate?

I'm trying to examine some instances where an X.509 certificate uses public and private keys for a paper I'm going to write. However, the only thing I have explicitly seen so far is in one of the ...
3
votes
2answers
2k 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 ...
5
votes
3answers
728 views

Digital Signature and Verification?

AFAIK , When Alice wants to write a message to Bob -- she uses Bob's public key and encrypt the message - and then Bob - using his private key - use to decrypt it. So public key is used to decrypt ...
5
votes
3answers
4k 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, ...
377
votes
3answers
160k views

How does SSL/TLS work?

How does SSL work? I just realised we don't actually have a definitive answer here, and it's something worth covering. I'd like to see details in terms of: A high level description of the protocol. ...
6
votes
3answers
499 views

What risks would exist in transmitting an encrypted PKCS12 via Https

I have a scenario in which I would like to automate the deployment of client certificates generated by an issuer I control. The approach I am considering is given below, and I would appreciate ...
3
votes
2answers
143 views

Using a verified certificate to sign others

OK my Google Fu has failed me as I'm not exactly sure what I'm searching for. This relates to PKI ad certificates generally but websites more specifically. Could you get a verified certificate from ...
4
votes
1answer
77 views

Standards for CA cert revocation and time-constrained cryptographic algorithm parameters

I'm working on software that will be in use for foreseeable future (15 years+) that will need to validate XAdES-A signatures (long term archival, similar to PAdES-A, but for XML). That means, it will ...
5
votes
1answer
101 views

Is it possible to have multiple key lengths in PKI?

Is it possible to have multiple key lengths in a PKI? For example, use a 1024-bit key for the issued certificate, a 2048-bit key for the intermediate certificate, and 4096-bit key for the root ...
3
votes
1answer
152 views

CMC (RFC 5272) compatible CA server

I need a CA server or any tool that supports Certificate Management over CMS (CMC) format, described in RFC 5272 (RFC 2797). I need a possibility to generate different Full PKI requests and responses ...
3
votes
1answer
76 views

Within a CSR, is there a field to have the MS PKI server change the default cert filename

I'm not intimately familiar with MS PKI, but it was a question that came up in a discussion for an issue a coworker is having. When you input the request fields manually on a PKI server, the cert ...
5
votes
5answers
2k views

Is Spoofing a CA signed certificate possible?

I had never thought about this situation before, I may be completely wrong but I am going to have to clarify it anyway. When a communication starts with a server, during the client handshake, the ...
1
vote
3answers
1k views

RSA encryption : How to create “.arm” certificate file for Public key?

I am required to store a certificate as ".arm" file only for a public key that is intended for use in RSA Encryption. I am currently able to generate the public key as ".key" file. P.S I am new to ...
16
votes
4answers
5k 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 ...
2
votes
1answer
131 views

Curious about best start for autoresponding Certificate Authority (CA)

I am just getting started trying to implement some internal PKI ideas, where my app would need a cert to 'sign' messages. Since this is all completly internal, we have some degree of trust, and I ...
2
votes
3answers
342 views

Transfer Client Certificate

What, if anything, could or would be embedded into a client-side certificate that would prevent it from "working" when transferred to a new client machine on a new network? Being unfamiliar with the ...
0
votes
1answer
230 views

Can I export my digital certificate to this emtec usb

It is said here http://www.emtec-international.com/sites/default/files/s530_aes_en_0.pdf 2048 bit RSA module: ready for PKI application SHA256 data hashing: ready for digital signature Does it ...
4
votes
1answer
1k views

Any reason not to use same key for multiple SSL domains on one server?

Assume I've generated a server key for use by Apache for SSL. The server will be handling several different domains that use SSL via unique IPs (no SNI). I want to generate a CSR for each domain from ...
13
votes
4answers
10k 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?
1
vote
3answers
606 views

Please recommend best-practices documents for sharing encrypted data with non-technical end-users

Is there one, or several, "best practices" documents which cover in clear simple language how to share data among a non-technical support staff and non-technical end-users at various organizations? ...