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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Export non-extractable private key from Keychain on OS X

I have a PKI certificate in Keychain Access.app on OS X 10.9, together with the private key. The manual page for /usr/bin/security indicates that there is a -x option for security import to specify ...
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35 views

Is it possible to distinguish between a SHA256 hash and an ecc256 key?

If an attacker were just given 256 bits, and they were either a SHA256 hash or a 256 bit elliptic curve key, would they be able to tell which one it is? Just out of curiosity, would they be able to ...
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9answers
2k views

How can I share files with other individuals using the cloud in a secure way?

I would like to use a dropbox because it is easy and convenient. But I want to encrypt the files with the public key of the intended recipient, so he will be the only one who can access the data in ...
7
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2answers
263 views

How can we revoke all ssl certificates issued for our domain?

After having the hostmaster@domain.com email compromised, we found that someone issued a Domain Validated SSL certificate for our domain. Now we want to have all such certificates revoked. Is there ...
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3answers
276 views

How does encryption/decryption work when one generate random key?

I am new to this and want to ask a basic question. Suppose I used my password (say "ABC123") to generate a key using the PBKDF2 algorithm (or any such algorithm). For encrypting a file I'll input my ...
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2answers
69 views

Encryption mechanism

I want to send data over the Internet securely. For that, I am using an public key of the receiver to encrypt the data. In this case, if an intruder in the network modifies the data, like placing the ...
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0answers
38 views

How can I generate some public and private keys on both sides with low overhead?

We have an Authority Center (CA) generating some public and private keys for each client (more than one pair for each client). One method for sending keys to client is sharing a secret key between CA ...
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23 views

Secure access of web application on a newly created AWS instance using the associated keypair

I create an AWS instance using a private AMI (Linux) with an embedded web application (Jetty) which is activated on instance start. As soon as the instance is launched first time, I want the ...
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1answer
153 views

adding certificate that resides on smartcard to the microsoft store with private key ownership

how can we solve CryptAcquireCertificatePrivateKey fails with 0x8009200B when adding certificate from smartcard to local user store? in an enrollment system where users generate smartcard certificate ...
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1answer
34 views

How to safely renew user and CA certificates in a PKI

I am currently developing my own PKI where x.509-client-certificates are issued by a public server. At the moment, the CA-public key is distributed with the binary and there are no routines for ...
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4answers
28k 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 ...
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0answers
38 views

What's stopping DANE? [closed]

As I understand it, DANE (RFC 6698) is a promising candidate for addressing issues with current TLS Trust Anchors (i.e. Trust Anchors). My attempt at explaining the issue: Currently, CAs are ...
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1answer
54 views

Is there any mechanism to audit which signed certificates are unrevoked?

We are currently using EasyRSA and OpenSSL to manage our user VPN certificates for OpenVPN. The process we have in place currently is: User generates a CSR on their laptop and sends it to us to sign ...
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1answer
202 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 ...
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2answers
56 views

Client Authentication Certificate Not Expiring, but “parent” cert IS

So I have a client-authencation cert installed on client PCs, which doesn't expire for 5 more years. Unfortunately, the cert on our gateway which is used to validate the client cert, expires this ...
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2answers
139 views

How to prove flyer was (not) authored by specific person?

Let's say we create a flyer in some desktop publishing software (e.g., InDesign, Illustrator), physically print it and post it somewhere. We don't want inauthentic claims of authorship. Is there a ...
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12answers
4k views

How feasible is it for a CA to be hacked? Which default trusted root certificates should I remove?

This question has been revised & clarified significantly since the original version. If we look at each trusted certificate in my Trusted Root store, how much should I trust them? What factors ...
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2answers
54 views

What's the mitigation strategy for when a CA's private key is stolen?

I'm new to SSL/TSL and was wondering if you could walk me through the following scenario. Scenario Let's say I am one of a thousand websites that has a certificate signed by some certificate ...
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1answer
134 views

Generating ECDSA certificate and private key in one step

Similar to how it can be easily done for RSA: openssl req -x509 -nodes -newkey rsa:2048 -rand /dev/urandom -keyout example.key -out example.crt -days 365 I'd like to generate a ECDSA cert/key in ...
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1answer
58 views

X509Certificate - How to set validation Policies?

I have an X509Certificate (say Certificate-A) for signing purpose. While validating this certificate, I have to check its path with Intermediate & Root certificate which I have implemented fully. ...
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3answers
81 views

Trusting SSL and the Trust Chain

As we all know, when an SSL Certificate is assigned, there is a trust chain that is created for verify everyone from the Certificate Authority to the actual website's SSL Certificate. Thanks to a ...
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1answer
62 views

What should a client verify after getting a client certificate?

I have a client that generates a csr, sends it to a server, the server then sign it and return the certificate as a String. the String is then decoded to a x509Certificate (using Bouncycastle's ...
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3answers
3k 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, ...
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1answer
35 views

MITM protection, key distribution

I want to make sure each of my apps users only get their own data, and that nobody tampers with it or sniffs it in a MITM fashion. Encryption of everything should be the solution, right? But how do I ...
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2answers
30 views

determine X.509 certificate class

I am very familiar with OpenPGP but don't even use X.509 / S/MIME. I know that there are several classes for certificates (from email check to personal ID check). I would like to know how you ...
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1answer
50 views

What crypto prevents & detects “invisible” CAs? (e.g. in X509v4)

For this question, I'm calling an "invisible CA" one that Is signed by a root ca and exists as a 2nd or 3rd tier Is valid, not expired or revoked Has a different Public key than one that is ...
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3answers
142 views

From a trust perspective, is renewing a CA certificate the same as trusting a sub-CA?

I'm trying to understand the validation logic that would occur in the following hypothetical scenario An unpatched XP user who trusts a list of root CAs. Those CAs in particular have been renewed ...
354
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3answers
136k 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. ...
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1answer
209 views

Using client certificates for website authentication

I was wondering if there currently exists a Content Management System that supports PKI and client certificates for website authentication instead of username/passwords. If not, what's a good place to ...
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1answer
30 views

How to encode a username in PKIX certificate?

I was reading through RFC 5280, PKIX Certificate and CRL Profile, Section 4.2.1.6, Subject Alternative Name: The subject alternative name extension allows identities to be bound to the subject ...
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1answer
221 views

Open source solution to capture and decrypt SSH traffic (with private key)?

I am looking for a free open source solution that is able to capture and decrypt SSH traffic given the fact that I can provide the server's RSA private key (something like SSH CryptoAuditor). Please ...
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1answer
39 views

Are “Certificate Templates” used only as a “Template” or do they validate a certificate request?

I'm trying to learn how Microsoft Certificate Templates interact with a certificate request, and can only guess that they take on one of the two/three forms: They simply help the client create a ...
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1answer
89 views

Bastion host that allows jailed users to SSH but protects private key

Basically, I'm trying to let the user use a private key without having read access to it. Use case: Employee needs to SSH to a server in the data center. There is 1 private key for all servers, ...
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4answers
2k views

What web browsers support OCSP stapling? Are the privacy and performance features the same?

OCSP stapling decreases the load on a PKI infrastructure's OCSP server by attaching a signed OCSP response to the target in a TLS connection. In addition it creates a more secure/private session ...
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1answer
64 views

Automate the process of giving a user access to his encrypted messages, when the user loses his password

I'm implementing a way for users to share messages with other users. All users and admin-users have a unique key pair. A message can be sent from one user to multiple users. Admin-users, who always ...
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2answers
51 views

Data anonymization/ encryption requirement

I did check out the previous postings and didnt find what I was looking for- apologies if this is a repetition. I am working on an analytics engagement for a customer and he needs to share access to ...
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1answer
27 views

Temporarily suspending a Certificate Authority's Certiticate

The PKI RFC talks about revoking or suspending certificates. It also talks about revoking CA certs. However, I could not find anything about whether a CA or a Sub CA's certificates can be revoked or ...
2
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1answer
78 views

How do I get a third-party-signed ssl client certificate?

I've been given a requirement of providing a client certificate to authenticate between two application's web services. The other application (that I don't host) is requiring an SSL client certificate ...
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5answers
2k 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 ...
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3answers
47 views

Public key encryption vs Digital signatures

For same chunk of data, which one is faster? Public key encryption or digital signature? Confidentiality is not important. I am trying to achieve non-repudiation for the communication. Thanks!
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2answers
63 views

Should I use more than 2048 bits in my SSH-2 RAS Key?

I've been asked to generate a public key with PuTTY Key Generator. The default is 2048 bits, Should I add additional bits to the generated key? Or is it unnecessary?
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OpenTSA and PKCS11

We are planning to implement the time-stamping service(RFC 3161) using OpenTSA wanted to know If OpenTSA supports PKCS-11 (Cryptoki) to talk to HSMs? BTW: I did not find documentation or much ...
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1answer
99 views

x509 serial number - hex or decimal

When I run the openssl command openssl x509 -noout -text -in certname on different certs, on some I get a serial number which looks like this. Serial Number: 256 (0x100) On others, I get one ...
2
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0answers
22 views

1.3.6.1.5.5.7.1.12 Logotype extension - how can it be generated from openssl command line

If you look at this subCA Certificate from Verisign http://www.tbs-certificats.com/FAQ/en/495.html?p=en/495.html It has the following field 1.3.6.1.5.5.7.1.12: ...
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32 views

Openssl command line: How to get “Policy: X509v3 Any Policy” in a certificate I am generating through openssl

I am trying to generate a certificate through openssl which has the following line X509v3 Certificate Policies: Policy: X509v3 Any Policy But I end up getting X509v3 Certificate Policies: ...
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2answers
85 views

What are Implicit and Explicit Certificates in Public Key Cryptography?

A Public key is certified by a Trusted Certifying authority, to ensure the integrity of the key and authenticity of the entity who claims to have the corresponding private key. In this Public Key ...
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1answer
51 views

what harm can a malicious ca do?

If ca's act in the interests of an eavesdropper, what is the worst they cold do? I guess they can decrypt traffic not using perfect forward secrecy and impersonate the server. Is this the case?
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60 views

Public e-mail Encryption Certificate

I'm quite new to this, so don't be too hard on me. I'm currently using the CipherMail MTA to generate e-mail encryption certificates. I created an own CA and public and private keys for our contact ...
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3answers
121 views

Is storing the private key and public keys in same directory on server recommended, like OwnCloud does?

Is this recommended or a good/normal practice? I think not. Because I saw that OwnCloud stores all encryption keys in one directory on the server. One directory contains the private key(s) and one all ...
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2answers
49 views

Risk in connecting wrong ssh host?

I've a ssh host key login setup in a remote server, for some reason, the DNS of that host is mapped to another server. So assume the mistaken host cannot be trusted, should I change my key?