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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10
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4answers
1k views

Why should I sign data that's already encrypted?

My question is about the difference between signing and encrypting. Why would you still sign something if you are already going to PKI encrypt it? Doesn't the PKI encryption inherently provide ...
0
votes
1answer
29 views

Forward Secrecy not supported with referenced browsers?

I am running a scan against one of our servers from the Qualys SSL tester site and it says that my server "does not support forward secrecy with the referenced browsers". What exactly does that mean? ...
358
votes
3answers
143k 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. ...
7
votes
2answers
319 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 ...
2
votes
1answer
255 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 ...
0
votes
1answer
45 views

How are TLSv1.0 ciphers negotiated as TLSv1.2?

I'm a little confused about something I am reading in Bulletproof SSL. "TLS 1.2 is the only protocol that allows suites to define their PRFs. This means that for the suites defined before TLS 1.2 ...
4
votes
5answers
652 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 ...
0
votes
0answers
65 views

Do SSH private keys always contain enough information to derive a public key?

I am working on a persistence model for SSH Private keys. The technology used is Java. Since the persistence structure of the public and private keys is pretty similar and using some of the Java APIs ...
0
votes
2answers
49 views

ECDSA ciphers and forward secrecy question about key exchange

I have heard that with forward secrecy that the ECDSA ciphers generate different keys for "each session" because they are not dependent on the private key of the server. My question is how is "each ...
0
votes
2answers
79 views

What would cause a server to only send over 1 SSL certificate to a client?

We have a secure server that seems to only be sending over the identity certificate. Running the hostname through Qualys says that only 1 cert was provided. The intermediate had to be downloaded on ...
2
votes
1answer
613 views

Root certificate key usage (non-self-signed end entity)

This discussion does not include self-signed end entity certificates for hosts like web servers and mail servers. OpenSSL's default configuration for a CA certificate has the following keyUsage: ...
1
vote
1answer
37 views

ECDSA/RSA certifcates and cipher selection

In this image can someone tell me if a standard RSA certificate can support the EC*_RSA ciphers listed? If so do you create the typical RSA keys when you are creating the CSR? Also I am fairly ...
0
votes
1answer
50 views

Smart Token Security Test

I have a question. One of my colleague gave me a Smart Token which consists of public/private key inside and asked me if I can test its security. I said it should be tested in a equipped lab for ...
1
vote
1answer
187 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 ...
0
votes
1answer
70 views

What is the deal with Valicert SSL root certificates?

Does anyone know what the status of the "Valicert Class 2 Validation Authority" root certificate is or what's going on with Valicert in general? I've heard that that cert has been deprecated, no ...
1
vote
2answers
63 views

Does where I put my PKI certificates matter?

I have an intermediate and a root PKI certificate that I see were already imported into a computers (windows server 2003) certificate store. However both the intermediate and root certificates were ...
2
votes
4answers
137 views

SSL root certificate optional?

I may have been under the wrong impression on how servers should be setup and what certificates actually get sent over during the server hello certificate message. I came across this today from ...
1
vote
0answers
25 views

Key management for hosting applications

We're looking to host a number of client applications in our environment. Some of those will use crypto, e.g. for ssl or database encryption and obviously we'll need to manage keys for that. I am ...
-1
votes
1answer
46 views

Can a CSR be created in OpenSSL with SHA2?

Can a CSR be created in OpenSSL with SHA2? If so, what would the command be and what does this tell the CA, if anything? If you could create a CSR using SHA2 would it "tell" the signing CA to use it ...
1
vote
1answer
61 views

Self-signing client certificates and distributing them, is the following a sound procedure?

I have a case at hand as follows: There is a number of clients in Internet (i.e. untrusted channel), initially in hundreds but growing in numbers. There is a server doing processing related to these ...
0
votes
1answer
152 views

4096 bit RSA encryption keys vs 2048

Where do 4096 bit RSA keys for SSL certs currently stand in terms of things like CA support, browser support, etc? In the overall scheme of things is the increased security worth the risk of 4096 bit ...
0
votes
2answers
60 views

Typical mistakes when implementing digital signatures?

I am looking for a list of typical mistakes someone can make when implementing digital signatures for a software. And of course why they are mistakes and how an attacker could take advantage of them. ...
0
votes
1answer
25 views

Is there any benefit to providing multiple types of public keys?

Say I have a page on my website which lists public keys to be used in case people would either allow me access to a server, or send me encrypted information. Is there any benefit to me providing ...
3
votes
2answers
186 views

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 ...
0
votes
0answers
51 views

Public/Private key validation

Suppose I have this scenario: User --> Inputs License Key --> I validate it --> If success, good, move onto main window. If not, prompt the user to reenter the license key. The license key will not ...
0
votes
3answers
48 views

Digital Signature and man-in-the-middle

While reading this page about Public-Private key encryption, I asked myself a question about digital signature: Alice wants to sign a message for Bob; she uses her private key to sign the message. ...
0
votes
2answers
42 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 ...
0
votes
1answer
79 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 ...
1
vote
1answer
79 views

CSR from IIS 8 and Keeping my Private Key a Secret

I've been trying to understand something. When you generate a CSR from IIS, how is the private key kept as a secret, or is it? Do CA's email you a certificate that includes your private key? Because ...
3
votes
2answers
1k views

How does Authy's 2FA work, if it doesn't connect to the server?

I thought I knew how two-factor authentication works: I enter the password. Server generates a random number (token) and sends it to me via SMS. I enter this token. Server checks that the token I ...
0
votes
1answer
38 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 ...
0
votes
4answers
110 views

Using a Public-Key-Encryption browser side to avoid PCI compliance

We're developing a web application in which certain not logged users (clients) need to send their credit card details to other users (merchants) - which, we'll assume, are PCI compliant. We are ...
1
vote
2answers
58 views

Is there a secret-sharing public-key-encryption-based service? [closed]

I need to share some sensitive information with someone else who can only communicate via E-mail. I don't love the idea of sharing this information freely over email in plain text, so I was ...
0
votes
0answers
63 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 ...
7
votes
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 ...
0
votes
1answer
43 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 ...
1
vote
3answers
338 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 ...
0
votes
2answers
71 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 ...
0
votes
0answers
24 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 ...
1
vote
1answer
62 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 ...
47
votes
4answers
30k 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
0answers
39 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 ...
2
votes
1answer
59 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 ...
3
votes
1answer
220 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 ...
2
votes
2answers
63 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 ...
3
votes
2answers
141 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 ...
36
votes
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 ...
2
votes
2answers
55 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 ...
2
votes
1answer
61 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. ...
3
votes
3answers
85 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 ...