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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9
votes
7answers
487 views

Authencity of information displayed on an untrusted device

Suppose I have a (bluetooth/usb) device which needs to displays information on an external pc/phone. Is there a simple and effective method to garantuee that the information displayed hasn't been ...
5
votes
1answer
451 views

Is is typical to create both x509 and OpenPGP key pairs?

I'm looking into increasing my use of signed and encrypted "things" - LibreOffice Documents, Off-the-record chat, PDFs, emails, etc. I'm finding that some things only support x509 format-certificates, ...
4
votes
1answer
342 views

How is an Authenticode timestamp verified?

For an Authenticode signed file to be verifiable by Windows after the original signing certificate has expired (typically 1-3 years after issue), the file also needs to have a cryptographically signed ...
4
votes
3answers
365 views

Certificate Transparency

From what I read here, if the intermediate CA has been compromised, a fake cert can be issued and the privacy of the end-users could be compromised as well. In order to remediate this situation, ...
1
vote
1answer
1k views

Self-signed CA and combining wildcard and SAN certificates

I have created my own Certificate Authority and installed the certificate on a few computers. Now I have generated a server certificate with common name *.mydomain.com and Subject Alternative Name ...
3
votes
4answers
348 views

Evil certificate authority in public-key-infrastructure

Alice goes to the certificate authority (CA) and registers her public key for signature verification. She gets a certificate for this from the CA. Bob requests Alice' public signature verification key ...
4
votes
1answer
285 views

Suggestions on easy distribution/installation of self signed certificates & roots to mobile devices

Suggestions on easy distribution/installation of self signed certificates & roots to mobile devices I am a developer at a government agency in a developing country that has a web application with ...
0
votes
2answers
871 views

Client Authentication by certificates in Google APP Engine java

I am writing an application in Google APP Engine java which authenticate the user by its certificate. I have created a self signed certificate using keytool at client side. I also enable the HTTPS ...
4
votes
3answers
1k views

In what ways does increasing SSH host key length increase security

I have read on a few guides on "how to secure SSH servers" that it is a good thing to increase ServerKeyBits from the default of 768 to 2048. Most of these guides seem to be for the entry ...
-1
votes
4answers
208 views

Changing private keys [closed]

My question is a bit of weird one and doesn't apply to me so much as I'm just curious. My question is: If a large company (say, Google, Facebook, or a bank) were to have its private key stolen, how ...
3
votes
3answers
669 views

What stops a hacker from installing it's own CA certificate?

Taking a look at this (now rather old) article about the generated rogue DigiNotar certificates, it states the following: ...Such is the case with that small company in the Netherlands, ...
3
votes
1answer
106 views

In theory, can x509 certificates use Accumulator-based revocation schemes? How do these schemes work?

On page 3 of this U-Prove document regarding toke revocation, the author says the benefit of Accumulator-based revocation schemes is A cryptographic accumulator allows the aggregation of a large ...
1
vote
1answer
521 views

Additional security for WebRTC/DTLS-SRTP with PGP?

I am having a thought experiment. Can you help me? Two clients who both use PGP. They initiate a WebRTC call using DTLS-SRTP via a 3rd party server. Is there any benefit of encrypting, via their ...
0
votes
1answer
247 views

SSL (TLS v1.2) - Can i offer fallback CAs when upgrading Certificates? (Java)

I am currently developing a product that involves two network situations. At the client side, multiple computers form a P2P network (multiple locations, multiple p2p networks), and a subset of nodes ...
3
votes
2answers
324 views

Totally secure public key distrubition

Public-key cryptography secures communications provided that you use pre-shared public-keys. The problem is how to share these public-keys while maintaining authenticity? How can we be sure that ...
3
votes
3answers
2k views

Extracting the PGP keyid from the Public key file?

is there a way via an CLI tool or some kind of API to extract the PGP KEY ID from the PGP PUBLIC KEY BLOCK ? I did find the hexa value of the key in the binary file, however I guess the position is ...
1
vote
3answers
434 views

accepted naming convention for public keys/certificates

Is there an accepted naming convention for referring to PKI artifacts? There seems to be a lot of confusion with naming of artifacts. For example, it seems that some people refer to: public keys ...
4
votes
4answers
327 views

Biometric non revocable major flaw

The major problem with biometric methods of identification is that they are impossible to revoke. Once my fingerprint, under whichever form, is stolen, I can't put it on a worldwide revocation list, ...
14
votes
5answers
3k views

Are self-signed certificates actually more secure than CA signed certificates now?

Are self-signed certificates actually more secure than CA signed certificates now? I ask this because recent leaks about the NSA spy programs and the secret FISA courts mean that the US government ...
3
votes
4answers
522 views

How can we trust PKI, for example, Verisign?

We want to send an encrypted message to Alice. We can ask her a public key over the network, encrypt with it a message and send that message back. It is bad, because someone can pretend to be Alice ...
23
votes
5answers
3k views

Why is Bruce Schneier recommending symmetric crypto over public key crypto

I just read the article written by Bruce Schneier, the crypto guru. In the article, he says : Prefer symmetric cryptography over public-key cryptography. But, he doesn't shed any light as to ...
3
votes
2answers
238 views

Requirements for qualified certificates in DIRECTIVE 1999/93/EC

DIRECTIVE 1999/93/EC at ANNEX I Requirements for qualified certificates states that one requirement for qualified certificates is (a) an indication that the certificate is issued as a qualified ...
4
votes
1answer
88 views

What is the meaning of http://uri.etsi.org/TrstSvc/eSigDir-1999-93-EC-TrustedList/SvcInfoExt/RootCA-QC from ETSI TS 102 231 V3.1.2

From Technical Spec http://uri.etsi.org/TrstSvc/eSigDir-1999-93-EC-TrustedList/SvcInfoExt/RootCA-QC a Root Certification Authority from which a certification path can be established down to ...
3
votes
2answers
642 views

Possible to use a YubiKey in HSM mode to secure a Windows CA infrastructure?

I'm looking for a low-cost Hardware Security module, and discovered that YubiKey has a HSM mode. I'm not entirely clear if this HSM mode is what I'm thinking, but I'd like to use it as the offline ...
3
votes
1answer
2k views

How do I share my S/MIME public key?

I have setup S/MIME encryption for my email address, and I'd like to allow people to download the public key from my website, rather than having to first receive an email from me. I want the public ...
4
votes
1answer
488 views

What are the alternative to PKI certificates in mesh networks?

My particular problem has to do with secure communications over a mesh network (http://en.wikipedia.org/wiki/Mesh_network), in particular man-in-the-middle (MITM) attacks. The difficulty is that mesh ...
6
votes
2answers
658 views

ECC based Client Certificate import in Chrome/Mozilla in windows

I have deployed a PKI server and successfully able to generate the ECC based user or client certificates. but non of the web browser support ECC as public key. I have tried different tools and also ...
6
votes
3answers
9k views

Is it possible to use wildcard certificates on multiple devices?

I have a server that I want to use a wildcard cert on. It runs multiple services. I purchase a wildcard cert so that I can protect mail.something.dom, www.something.dom, im.something.dom, ...
1
vote
1answer
78 views

Bootstrapping dual SMIME certificates for signing and encryption?

To maintain the non-repudiation property of signing while still having escrow for the encryption key, it's recommended to have a separate certificates (and pub-priv keys) for signing (say CertSign) ...
12
votes
2answers
498 views

Is PGP secure against a rogue keyserver?

Imagine Eve taking over the keyserver both Alica and Bob are using. By replacing Alices and Bobs public keys with her own, she can do a man-in-the-middle attack decrypting messages and relaying them ...
3
votes
2answers
144 views

Deciding whether to sign someones key

How do i decide whether to sign someones PGP public key? I was looking at some contact pages and they have a request for people to sign their public key. How serious of a commitment is it to sign ...
2
votes
1answer
255 views

What is the optimal result for the elliptic curve patent issue?

I saw an article this morning, discussing the fact that RSA and DH may be significantly less secure in the upcoming five years. Although the chance that this will materialize is small, I immediately ...
4
votes
4answers
14k views

SSL Client Certificate authentication

Is it possible to make a program which uses client certificate authentication with only public and private key (I have not generated any certificate, I have only public and private key). Simply, I ...
-2
votes
1answer
183 views

Posting public key [closed]

Should I put my public key on my website so that people can securely contact me. I have seen personal sites where there public key is at the bottom of the page such as this site by the computer ...
1
vote
1answer
192 views

What's the point of public key servers, if they usually don't require any authentication at all upon upload?

Do they offer any benefits at all to the security of key distribution?
0
votes
1answer
478 views

Splitting up symmetric key to be able to encrypt using 1024 bit RSA public key

The application which I am writing generates a 256 bit symmetric key everytime it wants to communicate with the server and encrypts the data and sends it to the server. This is to avoid storing the ...
2
votes
2answers
2k views

Public keys on OpenSSL vs PGP?

It is my understanding that PGP permits multiple public keys, and in SSL you can only extract one public key? Is this correct? Is there any brief high level run down between the two. I don't feel as ...
2
votes
3answers
482 views

If a MITM has your public key and you are SSH-ing through the MITM, what is the maximum attack it can perpetrate?

Firstly, let me start by saying that I am not attempting to hack anyone or anything (not that I would know how or where to begin, if I were). For illustration purposes, let's call the primary key ...
5
votes
2answers
801 views

Root SSL certificates and browser support

I have given three certs to be install on nginx AddTrustExternalCARoot.crt PositiveSSLCA2.crt www_example_com.crt So I concat them into a chained cert cat www_example_com.crt PositiveSSLCA2.crt ...
5
votes
1answer
188 views

Password strengthening for PGP

I'm wondering about some of the semantics and security implications of using something like scrypt or bcrypt to "enhance" a password protecting a PGP private key. Essentially, I'm asking about the ...
1
vote
1answer
215 views

Generate Keytool Object from CSR

I have to develop an application which uses another application for generating a CSR. After generating the CSR I have to provide this CSR along with a SHA256 hash of the public key to a CA. The ...
3
votes
2answers
2k views

Checking SSL\TLS servers for null encryption support

I have a web server supporting SSL 3 and TLS protocols , the following are the supported cipher suites. TLS_RSA_WITH_RC4_128_MD5 TLS_RSA_WITH_RC4_128_SHA TLS_RSA_WITH_3DES_EDE_CBC_SHA How can i ...
3
votes
1answer
622 views

Can you make a digital signature using the receiver's public key?

My question is, can you make a digital signature using the receiver's public key and then have the receiver verify the signature using his private key? I always thought that in order to create a ...
5
votes
2answers
137 views

Is there a reason to encrypt an encryption key with a certificate before storing it?

Suppose my .Net application which is installed in the client encrypts a data. I want to use a different key generated randomly for each client so each client doesn't know the key of the other. Someone ...
3
votes
2answers
604 views

How safe is a PGP private key that has “escaped”, but without its password?

Assuming your PGP private key is protected with a password, and it "escapes", but the password does not, how worried should you be? Obviously in the real world, you would immediately revoke the key ...
3
votes
4answers
258 views

Trust among the root-CAs

The system of CAs with the root-CAs and their subordinate CAs are IMHO in principle akin to the system of banks with their main sites and subsidiries. In the case of banks, a customer of a bank ...
6
votes
2answers
713 views

Why do embedded systems store server's public certificate in ROM?

In the home automation scenario, smart gateway can bridge the many smart devices with Internet. In many cases, a server's public certificate is stored in the embedded system's ROM during ...
6
votes
1answer
153 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
1k 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 ...
4
votes
2answers
5k 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 ...