Questions tagged [pki]

PKI is short for Public Key Infrastructure. The foundation of a PKI is the certificate authority (CA), which issues digital certificates that authenticate the identity of organizations and individuals over a public system such as the Internet.

Filter by
Sorted by
Tagged with
1
vote
1answer
68 views

Why is factorial used in Pollard's $p - 1$ algorithm?

Why exactly do we use factorial for finding an $L$ which is divisible by $p - 1$? Pollard's algorithm is about B-powersmooth numbers & not B-smooth numbers. So where exactly does the factorial ...
2
votes
1answer
55 views

Does applying a “PushEntropy”-function increase security of a private key?

I was just reviewing the source-code of the NBitcoin-package. As far as i can see when you create a new bitcoin-keypair Key privateKey = new Key(); (without passing ...
0
votes
1answer
73 views

Automatic csr sending

In our project we have grpc server and clients which should satisfy mutual tls. So, there is CA and clients generate csr to sent to CA to signing it. Now I need to send csr manually to CA to sign it ...
1
vote
0answers
40 views

How does TLS 1.3 sign key exchange?

From this site: https://tls13.ulfheim.net/ and from https://tools.ietf.org/html/rfc8446#section-2 I can't find the part in which the exchange of keys is signed, isn't one of the parties "...
1
vote
1answer
46 views

Exploitability of AES in CBC Mode For Recovery of Plain Text

I'm aware of existing literature that shows in a comprehensive manner just how simple it is to tweak the ciphertext of AES-CBC such that the decrypted message ends up being entirely different than ...
0
votes
0answers
43 views

What are the rules regarding to numbers in RSA?

I'd like to have a small sanity check first: As far as I understand, diffie-hellman is all about that fact that, given the generator ($g$), the modulo ($n$) and the remainder ($c$), it's hard to find ...
5
votes
2answers
441 views

Clarification on the TLS verification process

I am reading this article in my attempt to understand how the TLS verification and chain of trust works. In the piece I come across a section that I am not sure I understand. In the simplified ...
1
vote
2answers
466 views

What exactly is Let's encrypts chain.pem file?

While trying to understand the use or meaning of the fullchain.pem file created by let's encrypt I stumbled upon this post in which ...
0
votes
3answers
65 views

What are the contents of a certificate and how can I view it?

I understand on a conceptual level that a certificate is nothing more than just a verified public key. The next question I have, is how exactly do I see the contents of a certificate? Apart from the ...
0
votes
0answers
28 views

Enforced complete decryption in pki schema

I want to use PKI to encrypt a message. How this generally done is to PKI encrypt an AES key and then encrypt the message. The problem(in my case) with this method is that you can also ask someone to ...
0
votes
1answer
77 views

Elgamal Encryption: Why does Bob get to reuse his keypair while Alice has to generate a new one for every message?

From Christof Paar's book The protocol consists of two phases, the classical DHKE (Steps a–f) which is followed by the message encryption and decryption (Steps g and h, respectively). Bob computes ...
2
votes
0answers
39 views

Why is confusion & diffusion not required PKI encryption schemes like Elgamal encryption?

The Elgamal encryption scheme is a Multiplicative Mask with the shared key. It doesn't seem to have any confusion or diffusion. So why is it not necessary here as compared to Block Ciphers?
0
votes
1answer
93 views

How to securely share AES key between two remote devices (client and server) through UDP protocol?

I have two separate system (client) and (server). I am having a problem which is to encrypt a message from the client and decrypt at the server. In order to do that, I am required to transmit my key ...
0
votes
1answer
68 views

What if the CSR is intercepted in transit while sending it to CA?

I was studying PKI the other day and I had a serious thinking about the following question. What is CSR? - It is a block of encoded text that is given to the CA when applying for an SSL certificate ...
3
votes
1answer
137 views

MPC protocols in plain/CRS/PKI models

I have seen that in MPC multiple models in different dimensions can be envisioned, like asynchronous vs synchronous networks, access to broadcast channels, and so on. However, a particularly ...
1
vote
2answers
318 views

What's the downside of using X.509 in SSH instead of PKI

ssh uses public keys for authentication and not signed X.509 certificates. Specify a drawback which would be the use of X.509 certificates instead of public keys. I've tried to look up a lot of ...
1
vote
1answer
96 views

Encrypt text message with Wireguard public key

With its public and private key(s), Wireguard looks a bit like PGP. But it is used for encryption of network packets and not normal text messages. I'm on a system with Wireguard already installed and ...
3
votes
1answer
1k views

Converting raw ECC private key into ASN.1 DER encoded key

I created a random integer array of 32 bytes to use as my private key for secp256k1 curve. ...
0
votes
0answers
52 views

FLT is partly applying to RSA equation, and also relation between ED mod phi and Phi + 1 mod N

After numerous attempts from myself and all of you guys, I finally came to understand RSA. I can now prove it and understand how I got there. But I still have some very few polishing questions. 1) We ...
3
votes
1answer
128 views

Relation between $N = P \times Q$, and $\Phi(N)$

When studying RSA, and proving simple concepts to myself, I went and understood groups and rings, but I failed to understand Lagrange's theorem. I did understand how from invertible finite groups I ...
0
votes
0answers
40 views

Conditioning access to private key?

I would like to provide a public/private keypair to a user, but require that the user obtain an authorizing key before being allowed to use the private key. I don't want the authorizing party to have ...
1
vote
1answer
88 views

In PKI, with a hash-encrypted message (first hashed, then encrypted), how is the plaintext ever retrieved?

Consider a normal PKI encryption flow - hash the plaintext, then encrypt the hash with the private key of the sender and then encrypt it with the public key of the recipient. All this is good - and I ...
2
votes
1answer
1k views

What is the difference between PKCS1 v1.5 and PKCS7? Is PKCS7 a superset of specifications in PKCS1 1.5?

I have a requirement wherein we have to verify the PE binaries generated for an aarch64 platform. These binaries are then signed using the opensource sbsign tool ...
2
votes
0answers
30 views

What are some examples of out of bound channels that work over the Internet in practice?

If I want to verify a public key (be it RSA, PGP, etc.) with another client over the Internet only, what are some viable out-of-bound channels for verification? Which channels have been used in ...
-1
votes
2answers
97 views

A simple misunderstanding of SSL/TLS

I just came to learn about Deffie Hellman Key Exchange. And a little bit about RSA. I came to DH from something about SSL. From what I understood before is that SSL uses DH and TLS uses RSA, but after ...
2
votes
1answer
180 views

Understanding need for PKI

For simplicity let's say I only have RSA and AES on my hands and I want Alice to talk with Bob over a secure channel. With secure I am implying no MITM and Alice and Bob know they are talking to each ...
1
vote
1answer
56 views

How are certificate status obtained on browsers?

There are two ways of checking the status of a digital certificate:- Offline Authentication (CRL) Online Authentication (OCSP, SCVP) Several browsers (like Mozilla Firefox) have given up the use of ...
1
vote
1answer
1k views

How is Cross-Certification implemented?

I am currently learning about Certificates in Public Key Infrastructure. Cross-Certification exists as an alternative because the concept of a single monolithic CA certifying every possible user in ...
1
vote
1answer
67 views

Nomenclature of Certificate Authorities and Certificates in PKI

In PKI there are different terms to identify certificate authorities in the chains. All terms I know of are as follow: Root Subordinate Super Intermediate I see all terms used interchangeably in the ...
1
vote
0answers
48 views

Sign file (Client-Server) PKI-CA [closed]

I have a use case, the IoT system sending a signed file to the data center and I have an internal CA to read the corresponding public key to verify the signature on the signed file. I am not sure ...
0
votes
1answer
2k views

Windows certreq full response file [closed]

I'm using the Windows certreq command line tool to submit a CSR for signing to a Windows Server CA. ...
1
vote
1answer
89 views

Include TSA Certificate in Timestamp Request

I'm currently working on Timestamping and stumbled upon a parameter fRequestCerts/requestSignerCertificates/certReq that according to the documentation (1, 2) tells a TSA to include the certificate ...
1
vote
1answer
75 views

How are public keys securely and reliably obtained across the internet?

I've just decided to start learning all about PKIs, and I have come across what seems like a paradox. When fetching a public key from either a server or a CA, how can we be sure that the public key ...
1
vote
2answers
89 views

PKI Multiple Samples start to expose Private Keys?

My understanding is that using a PKI, public/private key pair is generally secure to send message to people. That is, encrypt a message using the recipient's public key so they use their private key ...
1
vote
2answers
267 views

Characteristic of Public Key?

Is Public key used directly to encrypt a message or it is used to derive other keys ? Can we decrypt a message with same public key using which it was encrypted ? So far I understand, as PKI is based ...
3
votes
1answer
131 views

What is the RFC order of peer certificate verification, trust chain or expiry first?

If a certificate received from a peer: Is expired, has a valid signature, but from an untrusted root CA What error should be thrown? Untrusted certificate or expired certificate? I can't seem to ...
2
votes
1answer
213 views

HMAC computation using AES key

I want to compute an HMAC value of a data set using CKM_SHA256_HMAC mechanism with AES key. I have the error code CKR_KEY_TYPE_INCONSISTENT because it seems that I need to use a key of key_type ...
-1
votes
1answer
1k views

Creating multiple “public” keys from one private key

Is it possible to create a public key out of a private key, then create another public key from the first public key. And treat the first public key as a private key (So you have two levels of private ...
1
vote
0answers
13 views

Asymmetrical encryption with multiple sufficient key-pairs [duplicate]

I have the following requirement: There are N public/private RSA key pairs. The encrypted data must be decryptable by any of the private keys alone, but not by any other key. For encryption, the ...
2
votes
2answers
1k views

Can public key cryptography survive quantum computers? [duplicate]

Quantum computation is based on the superposition principle of quantum physics. Bits in a normal computer are either 0 or 1. Quantum physics allows bits to be in a superposition of 0 and 1, in the ...
2
votes
0answers
25 views

Authenticating to wireless with EAP-TLS in separate forests with the same trusted root CA

I'm looking at a scenario of having a standalone offline root CA sign a subordinate CA in two separate active directory forests on different campuses. If I then set up EAP-TLS on each site, will I be ...
2
votes
1answer
143 views

Can root and intermediate CAs use different asymmetric ciphers and key sizes?

For example, could a root CA use RSA-4096, one intermediate CA use RSA-2048, and another use ECDSA-256 (DH19)?
0
votes
2answers
550 views

PKI Validation - Usefulness of the public key with the identity certificate

I have some understanding of how PKI works, similar to this: - https://knowledge.digicert.com/solution/SO16297.html - https://security.stackexchange.com/questions/59566/ssl-certificate-chain-...
2
votes
1answer
1k views

What happens when a root CA loses its private key?

Certificate Authorities normally keep their private keys inside dedicated Hardware Security Modules (HSMs). What happens when such a device is lost (fire, electronic fault, stolen, etc)? How would ...
1
vote
1answer
734 views

How to sign a CRL file if I have offline keys?

I am generating a CA for internal use. When generating a CA, the best practice I have observed is to keep the root CA offline and emit an intermediate CA certificate that will in turn emit the end-...
3
votes
1answer
3k views

Does maximum length of CN in a x509 cert include the length of the OIDs?

This is a CN from a x509 certificate (I have done some substitutions just to mask the data but the length is not changed) CN=Alex Perry/pseudonym=88b2e76beE0e4e4b94b502020202262E/x500UniqueIdentifier=...
-1
votes
2answers
1k views

How does registration authority verify entity's identity for SSL? [closed]

In the answer here: Verification of identity by certification authority, it states that for European eIdentity you must provide your passport or ID card, but that this practice is quite different ...
3
votes
2answers
219 views

Encryption in a Distributed PKI?

Given a PKI infrastructure with a root node that signs CSR's for nodes Alice, Bob, and Carol. Is it possible for Alice to encrypt some information, store it publicly somewhere, then later Bob or ...
16
votes
1answer
1k views

Who issued the first SSL certificate?

When SSL was introduced in ~1996, there was only a few CAs issuing certificates for that specific use and a few sites which actually used SSL. Which Certification Authority issued the first SSL ...
1
vote
1answer
423 views

sign data and append certificate VS sign data and certificate

I am currently writing my masters thesis in which I need to develop a licensing module for an application. The license itself is a JSON Web Token which is signed using a RSA private key. Since we ...