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 ...

learn more… | top users | synonyms (1)

4
votes
1answer
82 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
111 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 ...
7
votes
4answers
1k views

Alternative to “web of trust”

Let's say I have an SMIME platform where I want to easily establish trust across the entire world for a particular purpose, for example for sharing valid financial information. I think that a ...
8
votes
3answers
2k views

Is it safe to store a single symmetric key encrypted with several different RSA public keys?

For the field-based encryption of a database containing sensitive information, I was thinking of the following design: Every user has a smartcard used for client certificate login. After login the ...
17
votes
2answers
8k views

How does RSA encryption compare to PGP?

On this answer ck says RSA and PGP are different. What you are essentially asking is how do I run my petrol car on diesel? The answer is you can't. I would be interested in a more ...
2
votes
1answer
144 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 ...
11
votes
4answers
1k views

What kinds of SSL certificates are usable for encryption?

I know that Verizon SSL certificates cost close to $600. There are couple of cheap alternatives, but I never really understood why Verizon does not offer such certificates. Look for RapidSSL at ...
1
vote
3answers
2k 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 ...
2
votes
3answers
468 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 ...
2
votes
2answers
100 views

Does it make sense that OCSP returns state for the signer CA itself

I have seen an implementation that in signature verification time searches for OCSP responses signed by the CA validating the status of the CA itself, so my question is if somewhere (maybe RFC2560) ...
0
votes
1answer
313 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 ...
5
votes
1answer
2k 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 ...
2
votes
3answers
779 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? ...
3
votes
2answers
505 views

Mitigations for Windows clients that don't support OCSP Nonces

Windows 7 clients (and older) don't support NONCES, a key feature used in securing the revocation check. Without a NONCE a MITM could replay a previously signed response and alter the validation of ...
8
votes
1answer
3k views

How does adding a random serial number improve a certificates' security?

This article says: "Finding collisions is a tricky process, since it requires you to muck with the bits of the public key embedded in the certificate (see this paper for more details). Also, ...
3
votes
1answer
530 views

Is the Netscape SMIME extension still required in a certificate?

Every Windows 7 host has a Trusted Root certificate from Entrust that has the "Netscape Cert Type" extension (see image) I'm comparing inter-operable S/MIME extensions and see a pretty diverse set ...
1
vote
2answers
198 views

S/MIME and Dual-use certificates

My assumption is that S/MIME almost always utilizes certificates as follows: My certificate can be used to allow people to encrypt messages and send them to me. My certificate (the same ...
5
votes
1answer
2k views

Can a certificate have multiple chains and multiple self-signed roots?

The following MSFT document has this paragraph: All possible certificate chains are built using locally cached certificates. If none of the certificate chains ends in a self-signed ...
2
votes
1answer
1k views

What are attribute certificates? Why would someone partition a certificate by reason codes?

In "How Certificate Revocation Works" a brief mention of Attribute Certificate and Reason Code partition is made: If validated by a client that supports partitioned and indirect CRLs, the IDP ...
2
votes
1answer
4k views

Clearing IE temp files don't erase CRL history. How can this be purged?

Even after I purge all my Internet temporary files, I still see information when I type certutil -urlcache How do I purge this information?
1
vote
1answer
5k views

What are the OIDs (KU and EKU) necessary for Smart Card Authentication in Windows?

MSFT smart card authentication is listed in PKINIT RFC 4556 however I don't see any OIDs listed. Based on this and this KB article the EKU section of the certificate should contain "Client ...
4
votes
1answer
2k views

how do extended validation X.509 certs work?

https://www.forumatic.com/ uses an extended validation cert. wikipedia.org's entry on extended validation certs says that a cert is known to be an extended validation cert if the OID in the ...
0
votes
1answer
1k views

URIs in the subjAltName X.509 extension

The subjAltTag extension for X.509 certificates can take in domain names, email addresses, URIs, etc. I was playing around with an X.509 whose subjAltTag had just a URI in it doesn't seem to work. ...
2
votes
3answers
887 views

why does the first certificate have a RSA public key in x.509?

Example from http://en.wikipedia.org/wiki/X.509#Extensions_informing_a_specific_usage_of_a_certificate 1st certficate - freesoft 2nd - CA thawte Don't we use the RSA public key from the 2nd ...
3
votes
2answers
1k views

What encryption schemes require two or 3 private keys to read a message?

I would like to encrypt some data so that it can only be read if two or three people use a private secret to decrypt the data. What is the best / most modern way to accomplish multi-person ...
1
vote
1answer
114 views

valid intermediate certs not in browser

Say an X.509 cert is signed by an intermediate cert that's not in your browser. Maybe the root certificate is but not the intermediate cert. At that point it seems like a valid certification path ...
7
votes
3answers
3k views

Why does OpenVPN require securely sharing certs with clients?

The ubuntu docs on OpenVPN have this part in the instructions: Copy the following files to the client: /etc/openvpn/ca.crt /etc/openvpn/easy-rsa/keys/hostname.crt ...
4
votes
3answers
670 views

Public key system confusion

I read the following about PKI: Using a public key system, a user may encrypt a portion of a document using his or her private key. This message will later be decrypted by the recipient using ...
16
votes
2answers
1k views

Encryption and the “security time decay” of prior encrypted data

This question is on the assumption that any data once encrypted, may (eventually) be decrypted through Brute force (compute power/time) Exploits in the cryptography used Theft of private keys ...
1
vote
3answers
2k views

Firefox detected an invalid SSL certificate

February 14, 2012 UTC: Yesterday, I connected to a website of a VPN provider for which Firefox 8.0.1 on Windows 7 Ultimate x86-64 stated that its' SSL certificate is invalid. I saved the received ...
0
votes
1answer
374 views

Enterprise Encryption Considerations

What are the different aspects to consider for Enterprise Encryption policy? So far the resources I have are: https://www.owasp.org/index.php/Cryptographic_Storage_Cheat_Sheet ...
12
votes
4answers
22k views

Recommendations for a Certificate Management tool for Linux [closed]

A client is looking to roll out OpenVPN to all its mobile employees and will use certificates on both the server and all clients. This creates a new challenge to manage all these certificates and ...
5
votes
4answers
459 views

What fields in a suspicious certificate should I look at?

Looking at a certificate for a web-site (in Windows/Google Chrome) I see it lists the following fields Version Serial number Signature algorithm Issuer Valid from Valid to Subject Public Key Basic ...
3
votes
2answers
396 views

Null content digitally signed message

IA technical specification I'm following requires me to send: The Digital Signature must be in the form of a null content Digitally Signed message (i.e. a PKCS#7 object containing the signature ...
7
votes
3answers
1k views

What are the pros and cons of outsourcing an organization's PKI?

I am looking for the pros and cons of outsourcing an organization's Public Key Infrastructure (PKI). I understand that the answer to whether or not to actually outsource is going to depend on the ...
15
votes
3answers
4k views

Computationally simple, lightweight replacement for SSL/TLS

Target hardware is a rather low-powered MCU (ARM Cortex-M3 @72MHz, with just about 64KB SRAM and 256KB flash), so walking the thin line here. My board does have ethernet, and I will eventually get ...
8
votes
2answers
909 views

security of PKI, Certificates, certificate authorities, forward secrecy

I want to understand how certificates add to the security of information exchange. Suppose i have a encrypted bidirectional connection between Alice and Bob, using a public key/private key pair. As ...
6
votes
3answers
434 views

Why are CA's signing keys available on the internet

I am not very knowledgeable about CA certificates, but I thought these things mainly said "The public key for bank X is Y, and this is verified by CA Z". Once you've bought this certificate, there is ...
3
votes
1answer
819 views

What kind of certificate do I need to be able to make and sign my own digital signing certicates?

At build time for a program, I would like to generate a new key pair, and create a certificate that will be embedded (securely) into the program. The purpose of the key pair is to digitally sign an ...
4
votes
2answers
755 views

How practical is a certificate's “basic constraint” property in protecting my HTTPS / SSL session?

Suppose a leaf node creates a certificate for a different domain, acting as a CA. Do most popular frameworks, or SSL chain validation tools verify the constraints? Are there any I should be ...
5
votes
3answers
190 views

Guarding against rogue certificates

There has been a lot of news recently about certificates being falsely issued (due to the issuing authority having poor system security!). Apparently the targeted users were mostly Iranians, but it's ...
7
votes
2answers
466 views

Geographic equivilent of RFC 3161 (X.509 PKI Time-stamp Protocol)

First time poster here, hope to be around more often. I'm in need of a cryptographically secure 'stamping' system that allows not only time but also location to be attached to data, while still ...
8
votes
1answer
327 views

distributing files to VPN partners

suppose i've created VPN certificates for a certain VPN-RoadWarrior-Client, expressed in the files VPN-RoadWarrior-Client.key and VPN-RoadWarrior-Client.crt*, however VPN-RoadWarrior-Client is ...
6
votes
3answers
1k views

Certificate chain

For my computer to verify the identity of a certain certificate should it have all the certificates up to the root certificate?
0
votes
2answers
197 views

Create a certificate signing request [closed]

can someone please tell me a few tools that can be used to create a CSR ?
5
votes
2answers
3k views

Dealing with expired or revoked signing certificates with Infopath documents

Suppose I have an Infopath form that is digitally signed today by a valid, and active user. When that user leaves the company, we disable the account and revoke the certificate. This causes a problem ...