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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2
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1answer
91 views

What is the difference between a digital signature and whole message encryption?

I am newbie in information security I am trying to understand the difference between a digital signature and encryption of a message. Lets consider simple example of email message. I understand how ...
1
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1answer
22 views

Is there a secure method of distributing keys to network-booted diskless nodes?

I have a bit of an 'initial trust' issue. We are using CoreOS to run Kubernetes, and secure both the etcd API and the Kubernetes API servers using client certificates. We are using iPXE to boot ...
-1
votes
1answer
41 views

Same certificate but different private keys on different servers. Does this work?

We have a SAN cert that is used on multiple servers. Is it possible to have the cert re-keyed and only use the new private key on a particular server while keeping all of our other servers using the ...
2
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1answer
44 views

What does it mean to sign a public key and what's wrong with signing someone else's key?

I just stumbled upon this comic and I'm not sure if I understand what's going on. I googled and I figured that somehow people can sign other people's public keys and then they that person is ...
1
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1answer
212 views

Distribute S/MIME public keys and CA cert for email security

I have my own CA. I want to distribute S/MIME certificates for 10 different users. I saw S/MIME keyservers from http://wiki.cacert.org/KeyServers, but I don't want to use public servers. What is the ...
0
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1answer
22 views

How secure is it to bundle unencrypted private key and a CSR into PKCS12 certificate?

I want to create a self-signed certificate to digitally sign my documents. I want to do so using my existing key pair, but to accomplish this I'd have to export my private key unencrypted into a file, ...
0
votes
1answer
19 views

Are there any risks in wrapping asymmetric encryption in symmetric?

The web app I am developing should be end-to-end-encrypted, but for slightly better user experience, I do not want the user to enter private keys into the client. Instead I am planning to store the ...
2
votes
1answer
625 views

Determine private key size using public certificate [duplicate]

I have a public certificate in a PEM (.pem) file -----BEGIN CERTIFICATE----- MIICsjCCAZqgAwIBAgIJAMA1YIQ2JLXDMA0GCSqGSIb3DQEBBQUAMBExDzANBgNV ... 29V/R9RZOoSBHDzGPL84wm4qojMuwQ== ...
3
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0answers
30 views

Will WinVerifyTrust return true for a file signed by a revoked certificate, before it was revoked?

I've seen mentions online that drivers that were signed by certificates that were later revoked are still trusted by Windows' driver integrity. Apparently if the file was signed before the revocation ...
28
votes
4answers
40k views

Expired SSL Certificate Implications

What are the security implications of an expired SSL certificate? For example if an SSL certificate from a trusted CA has expired will the communication channel continue to remain secure?
1
vote
0answers
46 views

Key Hierarchy and key Encryption

If i have two 56-bit DES keys, and I use these two key to encrypt a 256-bit AES key. Like this: K_AT encrypts K_BT and K_BT encrypts K What is the effective security of key K? Is it 2 X 56 Bits?
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0answers
20 views

key hierarchy management and master key

Now, I have this equation, {{K_ab}K_bs}K_as. K_ab is encrypted by K_bs then whole packet is encrypted by K_as I think the key structure is K_as is the master key, K_bs is under K_as and K_ab is the ...
1
vote
1answer
58 views

Can Passpoint X.509 certificates be used to MITM SSL connections on Passpoint networks?

Passpoint/Hotspot 2.0 public networks like LinkNYC require users to install X.509 certificates, for EAP authentication. Can these certificates be used by the provider to execute man-in-the middle ...
6
votes
1answer
225 views

Are RSA Key Pairs unique?

I generate RSA key pairs mostly using the following command: ssh-keygen -t rsa -b 4096 -C "someemail@hostname.com" which produces a public-private RSA key pair. If I run this command again and ...
0
votes
2answers
26 views

Does PKI signature verification require secure distribution of public keys?

I'm looking at a software project where the GPG public keys of the maintainers are found on a website using HTTP. According to the GNU Privacy Handbook, "The signature is verified using the ...
0
votes
1answer
49 views

Review of a protocol

I am wondering if anyone could give a second opinion whether the following is secure or not. I have a system which consist of a mobile device, FTP server and a PC. The mobile device is to upload ...
663
votes
3answers
342k 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 ...
4
votes
1answer
90 views

Safely store passwords in specific scenario

I have a specific network environment. Its a DTN(Delay Tolerant Network) network without continous connectivity, situated on the sea, where nodes are ships. There is also a server that is a part of ...
3
votes
1answer
40 views

What security impact is caused by a TLS server continuing the handshake when presented with an invalid SNI?

RFC 6066 defines Server Name Indication as an extension, whereby virtualised web servers may be given an SNI extension in order to know which certificate should be presented. It has the following to ...
1
vote
1answer
59 views

Can I move my private-key to a better token?

I recently purchased a personal signing certificate from GlobalSign - it wasn't cheap either. It arrived yesterday. GlobalSign gave me a "blank" USB security token device - a SafeNet eToken 5100. ...
1
vote
1answer
108 views

PKI management with easy-rsa

I recently setup an OpenVPN server with easy-rsa and have questions about certificate revocation: In the event that someone's private key gets compromised and I have to revoke the certificate with ...
3
votes
3answers
43 views

Is it possible to prove that a TLS server key has changed?

I know of a site that is currently using SSLv2 and I'm refusing to connect to them until they Disable SSLv2 Re-key their servers I'm insisting on #2 because due to DROWN, servers running SSLv2 ...
4
votes
2answers
84 views

Centralized key management for IOS and Android Code Signing

What is the best way for an enterprise to manage code signing certificates? The default seems to be that Apple and Android keys get stored by each developer on their machines. I see systems like ...
1
vote
0answers
43 views

find owner of private key

On one of the old dev servers I manage there is an RSA public and private key pair ~/.ssh/id_rsa.pub and ~/.ssh/id_rsa in a staging user account (used for automation and testing prior to ...
2
votes
1answer
262 views

How CERT.rsa is interrelated with PackageInfo signatures

I am a newbie in security and cryptography, but I am developing Android applications and now wanna to dive deeper into the Android security mechanisms. I am trying to understand how CERT.rsa (as I ...
14
votes
1answer
405 views

How would one verify that the public key from WhatsApp's servers belongs to the person I expect it to?

WhatsApp had recently announced end-to-end encryption on all communications. While that's an impressive move, I still have a big open question mark. The articles and this white paper suggest that the ...
4
votes
1answer
66 views

Should 'openssl verify' recognise an exceeded 'Path Length' constraint on a root/intermediate CA?

Background Following the guides here and here I am setting up a multi-level PKI. I have increased the pathlen config to 3, such that I can generate one root certificate that I can use to sign the ...
2
votes
1answer
93 views

Generating shared secret key using existing receivers public key and senders private key

I have the public key of the receiver, and the private key of the sender. I want to generate a new key by using the receivers public key and senders private key (also known as the signing key) to ...
1
vote
0answers
123 views

WhatsApp end-to-end encryption for all devices [closed]

The news is out, WhatsApp switched on encryption for a billion people. It supports all devices and encrypts texts, photos, videos and calls. There are so many questions that just came to my mind ...
0
votes
0answers
30 views

Where are certificate private keys stored in Windows 7? [migrated]

Using the certmgr.msc utility, I can access the windows cert store, but I still can't figure out where Windows stores the private keys. For example for a given certificate, Windows tells me that ...
14
votes
4answers
7k 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
2answers
88 views

sharing private key sTunnel

All of the sTunnel guides and implementations at work do the same thing, they say once the private key and the public cert are created on the server, you need to cat them together and then share with ...
4
votes
5answers
2k views

Why would someone want to encrypt RSS feeds?

I heard the idea of encrypting the RSS feeds using public key encryption system from someone and since then I am intrigued by the idea. But then I started to wonder what would be the basic need for ...
0
votes
1answer
1k views

Security weaknesses in using RSA encrypted MD5 hash of certificate content

Suppose you have an Internet banking site based on a secure web server running the HTTPS protocol via port 443. The server authenticates itself to clients through an X.509 certificate signed by a ...
1
vote
1answer
26 views

Impose certificate extensions through the certificate authority instead of the client

As I understand the creation of a x509 certificate is a simple 3 step process: The client generates a private and a public key. The clients generates a certificate signing request for the pair and ...
5
votes
2answers
82 views

Public key for SSH over the internet differs from a key for SSH over the LAN

I have a Raspberry Pi and can access it via SSH (authentication via user password) when my laptop is in the same network. Now I want to access it over the internet. I already set my router to forward ...
134
votes
5answers
94k 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 ...
7
votes
4answers
2k views

P12 - Extract public part (certificate) without knowing the p12 password

I would like to extract the public part of a revoked P12 which doesn't belong to me. I can't open it with KeyStore Explorer because I am prompted for the password, is it possible with OpenSSL ? The ...
0
votes
1answer
44 views

Two issuing CAs in a two-tier PKI (Windows Server 2012)

I'm planning to setup two-tier PKI in my environment. We have two remote sites connected via a VPN. I think it is OK to set up both Root CA and Issuing CA on the 1st site. But, for example, I have ...
7
votes
2answers
108 views

Verifying cryptographically signed files when the key has been revoked

This is mostly a question out of idle curiousity. If I use my private key to sign a file today, forming a signature, and distribute that signature with the document to someone they can then use my ...
4
votes
1answer
919 views

Encrypting/decrypting our license key

We need to provide a license key to customers for our application. The actual license is XML but we need to encrypt it and then in our program decrypt it. I think it is the following, but am asking to ...
0
votes
1answer
44 views

Authenticating a user by verifying a signature

Background I'm setting up an API which will be used primarily over HTTPS (only calls not needing any security what so ever is available over HTTP). Some aspects of it need to be accessed only by ...
58
votes
3answers
5k views

Why aren't IMSI catchers rendered ineffective by standard MITM defenses?

There's been a lot of reporting in the past few years about law enforcement agencies using IMSI catchers (also known as Stingrays after a popular brand of them) to intercept cellular communications. ...
3
votes
4answers
5k views

When should I use symmetric encryption instead of RSA?

I'm currently using GPG RSA keys to encrypt binary files. Many people recommend using symmetric keys to encrypt large files, and then encrypt the symmetric key with a public key. At what file size ...
6
votes
5answers
733 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, ...
3
votes
1answer
62 views

How can I enforce that an SSH private key has a passphrase?

My company is serious about security and willing to move to SSH key-pairs. Users can generate their SSH key pairs independently and I worry if they set a pass-phrase. Can I enforce this? Does signing ...
3
votes
2answers
117 views

Can a CN-only certificate bypass a name constraint if the CA goes rogue?

I am trying to cross-certify an internal issuer certificate, adding a name constraint for our domain. However, it seems that an attacker could bypass this protection by putting the desired host name ...
22
votes
7answers
3k views

Is there such a thing as public key steganography

One of the drawbacks of traditional steganography is that both parties need to exchange a secret key. Encryption had this problem too but circumvented this with public key cryptography. Are there ...
11
votes
3answers
415 views

How will SHA1 deprecation affect internal CA's?

I am hearing that the SHA1 Deprecation notices from MS/CHROME only apply to certs that are a part of a public trusted root program. This makes one believe that IE will have new logic built in to allow ...