Questions tagged [public-key-infrastructure]

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 certificate authority (CA). There are three main categories of PKI: Web / SSL certs, corporate networks, and Government ID / ePassport.

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91 views

SSL MITM Proxy Security - Can we rely on it?

In my organization, we have an SSL MITM (Man-in-the-middle) proxy (like ZScaler proxy). If I browse an HTTPS website and check the certificate, I can see that the proxy has issued a separate ...
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What is the best strategy for handling a compromised private key within the domain of firmware?

I have a firmware project that uses asymmetric cryptography for assuring integrity and authority of updates. The private key is stored within the company, and the public key is on the firmware to ...
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Why does the CSR state/province name need to be the same as the CA certificate?

This is more a conceptual question than it is about a bug/error I'm encountering. I am learning about PKI (public key infrastructure), and attempting to sign my own certifications by walking through ...
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Can I use a public / private keypair to secure traffic on my wifi on OpenWRT?

Wifi passwords are a pretty weak way to secure a Wifi Access point; is it possible to use a public / private key to secure traffic on a wifi access point which runs OpenWRT. I know I can secure SSH ...
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Which SSH security is stronger? 2 Factor or Public key

For SSH authentication, which is more secure? 2 Factor Authentication using a USB token/Google Authenticator(time based) OR Public/private key with password Or could they be both used at the same ...
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140 views

Digital signature using only x509 certificate

Is it possible to digitally sign a document only with a x509 certificate (ie public key)? We received a question from one customer saying that they wanted to sign a document using only a certificate. ...
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62 views

How do I verify that an ssh public/private keypair go together, is it different for openssl and ssh-key generated keys?

Generating a Private Key... $ openssl genrsa -out ./oci_api_key.pem 2048 Generate a Public Key...from the private key: I'm trying to generate a public key from a private key in PEM format (the ...
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A standard way to manually add a digital signature to a pdf file?

I've created a few certificates to use myself, but I find myself stumped when it comes to creating a certificate which contains a digital signature. First, how would I go about creating a standard ...
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Wrong size for EC key pair

I'm using OpenSSL to generate EC key pairs. I notice that the length of the keys as displayed by OpenSSL are exactly one byte longer than expected for both private and public Key. The 00 (first Byte ...
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How does the browser decide to accept a self-signed certificate?

As far as I know, with OpenSSL, you can self-sign your website's certificate. This means that the browsers that will connect your server are supposed to be willing to accept a self-signed certificate ...
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How to secure VPN credentials on end-user devices?

I have a VPN and PKI in place with MFA. My question is: What's the best method/solution for protecting the integrity and identity of end-user certs? I want to make sure that users only able to use VPN ...
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Accessing a permitted file from local file system securely

I am working on project which has more focus on user data security. Public key cryptography is being used in this and private key is getting stored to user device locally (computer local file system). ...
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How does LetsEncrypt.org's ACME work?

I found the technical paper on ACME's inner workings, but I still feel a bit confused about the ways Let's Encrypt's Domain Validation works. From what I already know, verification can be performed ...
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Is it a good idea to use asymmetric encryption for a chat application?

I am reading design documents of an internal Whats-app like chat application. Developers are planning to use asymmetric encryption to encrypt all messages. Every user will have a public/private key ...
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Cross sign two self signed root CA

I have two self signed root CA that was used for separate kubernetes clusters (say cluster A and B). Both CA is used to sign application certs in their respective cluster. However, one of the ...
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1answer
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Amazon Elastic Load Balancer and mutual authentication

Has anyone configured AWS ELB (Elastic Load Balancer) to do mutual authentication (i.e., authenticate both the server and client), probably over TLS. We're exposing a REST API using SSH and a shared ...
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Making a Windows cert say it's purpose is “Ensures the identity of a remote computer”

I want my cert to show up like this when I double click on it in Windows: (source: devcentral.f5.com) If I just double click on a random cert I get this: The cert that corresponds to that is this:...
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How do you use a public key to encrypt a string

I am oversimplifying but I understand that a public key is the product of two large prime numbers. In essence as long as the private key is kept private, the owner knows something that the outside ...
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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?
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Offline code signature verification scheme

Assume that I want to sign digitally updates for an offline appliance (lets say a limited linux VM). To begin with, such mechanism is not in place and the very limited OS doesn't have any CA ...
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Would DNSSEC and certificates for IP addresses be enough?

Using DNSSEC you can be sure that you have the right IP for a domain and using a certificate for the IP signed by someone you trust you know you have the right IP. Shouldn't this be enough to know ...
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how to import a private key in windows

Say I have an X.509 cert and a private key that corresponds to it. I can import X.509 certs easily enough into Windows but what about private keys? Is the only way I can do that by converting both ...
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1answer
108 views

Does the CT system “enforce” CA's to log issued certificates?

If a CA, who is otherwise acting good and participating in the Certificate Transparency system, were to issue a certificate without reporting it to any log, would this be noticed somehow? I'm ...
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Encrypting intellectual property on client side

Is it possible to effectively protect/encrypt intellectual property that is on the client side? Assume that I am selling a product (software) to clients, that contains intellectual data, for example ...
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percentage of X.509 certs using rsaEncryption as publicKey algorithm

Quoting 2017_TLS_Telemetry_Report.pdf: Not surprisingly, 2048-bit keys now protect 90% of the world’s TLS hosts. The use of 4096-bit keys have quadrupled, as a share of hosts, but we expect it to ...
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How do I store other people's ssh keys securely?

This is not really a programming question, but please hear me out. I am building a deployment tool, So using my application others can deploy their own application to their own servers. (just like ...
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91 views

What's the goal behind signing a CRL with an old certificate key?

I was reading a CPS/CP for a CA, and it mentioned that there's a possibility after rekey that you can still use the old key to sign CRLs of the old end user certificates verified by the old CA ...
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Where do TLS clients fetch intermediate CA certificates from? [duplicate]

When I use my browser (a TLS client) to navigate to a secure web page (e.g. https://example.com), during the TLS handshake, the browser will receive an end-entity certificate from the web server of ...
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Is ssh and public key scheme like ed25519 as safe as the hackability of your computer?

I am just learning Linux and I have setup ssh to connect to a server. To do that I need to generate the key for the ed25519 public-key scheme. Once generated, both the public key and the private key ...
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Extracting .p12 cert and key without OpenSSL

I've asked a question on SO, but was directed here since it might align better with this SE. The problem I have is that I need to extract the certificate and key in unencrypted PEM format for use in ...
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The difference between Subject Key Identifier and sha1Fingerprint in X509 Certificates

I have some SW that extracts certificates data and the SW utilizes OpenSSL. I am confused what is the difference between the subjectKeyIdentifier and the sha1Fingerprint. Both are hash values. My ...
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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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Creating X509 certificate in C using post-quantum public key algorithm?

I'm trying to implement a self signed x509 certificate that uses a post-quantum (PQ) public key algorithm as the public key algorithm. I looked at the openssl library in c, and the way it's done using ...
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Is OCSP Request Signing Necessary?

We can directly request OCSP Server for certificate status. Then why is there an option to sign the request? Is it to identify incoming requests or something?
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Possibility of faking someone's public key

I know how public key cryptography works; (very) simplified: Alice takes Bob's public key and sends an encrypted message with said key and sends it to Bob. Bob and only Bob can decrypt the message, ...
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How to achieve non-repudiation?

If I have a message that I need to send to another person, how do I achieve non repudiation ? Is digitally signing the message sufficient ?
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What happens if the private key of a Trusted Timestamp Authority is compromised?

what happens if the private key certificate of a Trusted Timestamp Authority used to sign the timestamps is compromised? If this private key certificate is changed, should all timestamps be re-signed ...
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1answer
776 views

TOTP: Storing symmetrical secrets

Is it just me or does TOTP for two factor auth seem like a step back to the days of digest auth where you have to store the symmetrical secret in a reversible manner. Passwords stored in plaintext ...
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Cannot understand supposed ProtonMail vulnerability from wired.com article

Currently I'm reading an article about ProtonMail here and I don't understand it. Now let’s address ProtonMail’s weaknesses. One of the big issues is that it isn’t easy to know whether a message ...
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Using same algorithm for signing and encrypting a message

If we use the same algorithm to encrypt and sign a message, what can happen if the message is intercepted and read by a third party?
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openssl verify signature

For S/MIME, I now know I can verify PKCS#7 detached signatures with: openssl smime -verify -in detachedsign.pem -content content.txt But what about non-MIME messages? So if I sign the message Hello, ...
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How can I mitigate the possibility of SSL private key being copied without my knowledge?

OCSP stapling and Certificate Transparency logs seem to provide a pretty good defense against man-in-the-middle attacks if I discover that my private key has been stolen. I can revoke my old ...
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Can I add a password to an existing private key?

Say I have previously created a private/public key combination, and decided at the time to not protect the private key with a password. If I later decide to "beef up" security and use a password-...
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1answer
489 views

Certificate Practice Statement (CPS) without CP (Certificate Policy)?

This previous question discussed differences between a CP and CPS. According to the RFC: The main differences between CPs and CPSs can therefore be summarized as follows: (a) A PKI uses a ...
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If I am able to generate the same public key as someone else, do I also get the same private key?

I have a very basic understanding of the asymetric encryption. I have a couple of simple questions. I know I can generate a key pair, of public and private keys. If by co-incidence my public key ...
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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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Symantec rooted certificates trust and Oracle Java trust store, is Oracle planing to remove trust as well?

We are using Symantec CA rooted certs to sign JARs. Since Google and Mozilla have indicated that they are not trusting Symantec CA, should I be concerned that Oracle will remove trust from Symantec CA ...
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Duplicate subject names for intermediate and root certificates

I work in an organization which is employing what I believe to be a non-standard and problematic PKI system for internally used certificates. They issue multiple root certificates and intermediate ...
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Revocation list for a custom solution

If I have a network of machines inside a company that use certificates for various services. All of these services and machines are internal and never have to deal with public facing technologies or ...
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How to understand the PKI's revocation of keys and certificates function?

A public key infrastructure is a collection of hardware, software, people, policies, and procedures that implement the generation, management, storage, distribution, and revocation of keys and ...