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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3 views

Reset Windows trusted certificates store to its default

Over the time I have installed several additional trusted CA certificates to Windows trust store, sometimes because an app pushed me to do so, some other times for development and testing. Is there ...
2
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1answer
221 views

Making a bitcoin-like secure mail protocol, how to tackle public keys?

I'm making a new mail protocol (probably already exists, but I've learnt a lot of things about security and privacy on the way). Here's the summary(much simpler if you know bitcoin's inner workings): ...
1
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2answers
44 views

What's the benefit of hybrid cryptosystem vs asymmetric for small data blocks?

It's a common belief hybrid cryptosystems are better than asymmetric only. Is that allways like that? What's the benefit of using symmetric and asymmetric encryption for small data blocks (< 100 ...
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1answer
64 views

How long can a pkcs#8 passphrase be?

A program is using a private key to read messages. To improve security, besides randomness, I'm trying to create the longest passphrase that makes sense. How long should it be? After which amount of ...
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1answer
115 views

What would cause a server to only send over 1 SSL certificate to a client? [on hold]

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 ...
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1answer
67 views

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 ...
375
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3answers
158k 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. ...
1
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1answer
350 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 ...
3
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2answers
2k 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 ...
2
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3answers
58 views

Best practices for GPG user ids

What is the best practice for choosing GPG user id(s)? I've read various bits of advice, which sometimes even contradict each other. For instance, I've read that one should not use comments, because ...
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0answers
11 views

IKE(v2) with pre-shared publc keys?

Is using IKE(v2) to only talk to a pre-defined set of peers by their Public Keys supported as part of the protocol? As in, for a given peer, can I give that peer a set of 3 public keys P1, P2, P3 and ...
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2answers
147 views

Is “HTTPS” ~100% secure? [duplicate]

Before I login to a trusted website, I always check that the address bar has a green padlock and the URL has no typos. E.g: After I've seen the green padlock and checked the domain ...
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0answers
28 views

Attack Vector for Wildcard Cert

So I am looking to the security risks of WildCard Certs, in a previous post most of the questions were answered however I have one follow up question for that. In my instance I use DigiCert, so ...
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1answer
52 views

Problem with common factor in RSA [duplicate]

In the RSA key generation steps, what if two entities select a common factor to generate n (i.e. p*q1=n1 and p*q2=n2) resulting in gcd(n1,n2) <> 1 ? This will lead to a problem that everyone ...
9
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2answers
4k views

How to set up OpenSSH to use x509 PKI for authentication?

I do not mean simply putting the public RSA key of a x.509 certificate into ~/.ssh/authorized_keys - I'm looking for a way to set up a ssh such that x.509 certificates signed by a pre-defined CA will ...
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2answers
134 views

With RSA, can one ensure that two entities will not have the same private key?

With the RSA encryption algorithm, is there any guarantee that two different entities will not be given the same private keys?
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4answers
1k views

Multiple CAs signing a single Cert/CSR?

Just saw this suggested on Slashdot So I've seen quite a few people wanting a switch to self-signed certs (who IMO mostly don't understand what making that secure actually involves), and an idea ...
3
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1answer
117 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 ...
53
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4answers
34k 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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5answers
119 views

Are most MiTM attacks done to impersonate web sites, or simply decrypt traffic?

The more I read about impersonating web sites the more I get confused. Does an attacker need the private key of the server in order to impersonate a website or does having the private key simply give ...
0
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1answer
105 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 ...
0
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2answers
55 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
65 views

Anonymiszing sensitive data in MySQL DB while retaining searchability

I have a MySQL database that stores sensitive (personal) data about individuals; and have been tasked with ensuring that this data is encrypted in some way to protect the individuals and their data if ...
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1answer
50 views

Recommended Key Usage for a client certificate

My program has the following flow: a client sends a CSR to server, the server sends back a client certificate and after that the client communicate with the server to a path that requires a ...
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1answer
71 views

Chat encryption system avoiding protocol sniffing and then key+decryption replay?

I'm working on a chat system and I want to add it some kind of security (not just HTTPS with SSL since I've read it can be sniffed and decrypted with a few tools). Now, my knowledge in cryptography is ...
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0answers
61 views

How do public/private keys work?

I have read "How does SSL/TLS work?" and "Public-key cryptography", and I know basically what happens when using a Public-key to encrypt/decrypt something. To sum up what I've read, A Public-key ...
0
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1answer
70 views

Why are CA's now signing root certs with SHA2?

I see that CA's are now giving the option of having the root CA cert signed with SHA2. I have been told that the hashing function in a root has no security value, and is irrelevant as far as a ...
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0answers
26 views

Webpage signature

Is there a way to sign each post of a provided hosted blog (wordpress.com in my case, not .org) with my private key? The goal is to provide the signature (at the end of each post) along with the ...
2
votes
2answers
50 views

The reason to insert Subject Alternative Names into CA certificate

I am trying to understand meaning of the Subject Alternative Name extension. The reason of usage it in SSL X.509 certificates or other end-entities certificates is mostly clear for me. However, I ...
0
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2answers
180 views

What does 2^77.1 calls presented in a SHA1 attack mean?

Regarding the SHA 1 deprecation, I found this information here: http://blogs.technet.com/b/srd/archive/2013/11/12/security-advisory-2880823-recommendation-to-discontinue-use-of-sha-1.aspx I know ...
1
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2answers
93 views

Does adding multiple recipients to an encrypted message decrease security?

Let's say you want to send the same GPG/OpenPGP encrypted message to 50+ recipients. Assuming everyone you send to is trusted, and there is no risk of any recipient leaking their secret key, is ...
0
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2answers
66 views

Does a smart card do encryption or does it just provide a private certificate?

I don't really understand how smart cards work. Do they sign or encrypt themselves (where the computer provides data to it to sign) or do they provide a computer with the private certificate when I ...
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2answers
45 views

Can Subject Alternative Name(SAN) Certificate install on different Web Server or OS?

Let say: application.house.com apache tomcat : physical server email.house.com apache tomcat : virtual finance.house.com Oracle Wallet Manager : physical server ...
2
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1answer
520 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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2answers
1k views

Cryptography behind chip based credit cards (smart cards)?

Why are chips safer than magnetic stripes? The answers to the above question explain that the chip based cards can not be cloned as the "secret number" is embedded in the chip and protected by the ...
2
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1answer
57 views

Which PGP settings have been found to be vulnerable?

Digging through articles, one often finds recommendations such as "Use the default key type/size X", whereas an article written a few years later will write "Key type/size X has been found to be ...
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1answer
29 views

What happens if my signing subkeys are compromised?

Let's say my subkeys are compromised, but my master keypair is safe and secure, so I revoke the old subkeys and issue new ones. With encryption keys, the results are pretty clear: I can still decrypt ...
3
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1answer
42 views

How long to keys stay on keyservers?

Do GPG/PGP keyservers "garbage collect" old keys which have expired, been revoked, or simply haven't been updated in a decade? Or does the server (theoretically) keep every key it has ever seen from ...
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0answers
9 views

Is it possible to use certutil to export multiple certificates from a local client machine store, to a .p7b file? [migrated]

Is it possible to use certutil to export multiple certificates from a local client machine store, to a .p7b file? Scenario: We have a few legacy certificates based on some legacy templates (2012 R2). ...
0
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1answer
68 views

Smart Token Security Test [closed]

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
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1answer
101 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 ...
1
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2answers
94 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 ...
8
votes
3answers
1k views

Anything to do about old gpg keys?

Quite A few years ago (in middle school) I created some gpg keys, published them to a keyserver, etc. because I was l33test kid on the block. Now I have gone through a few new computers and OS's, ...
1
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0answers
42 views

Protecting data on a remote device

Background I have am developing a service which consists in a small headless client device (e.g. OLinuXino) which will contain sensitive data. The device will be plugged to a remote network (maybe ...
2
votes
1answer
41 views

Is distinguished subject name at normal SSL Certificate issuance must same as generated Certificate Signing Request (CSR)?

For example: from Issued SSL Certificate: CN = abc.com.my, OU = Room, O = House, c= MY from generated CSR: CN = abc.com.my, OU = Room , O = House, L = KL, ST = KL , C = MY Questions: 1. Is it ...
2
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1answer
52 views

OpenVPN: Storage location and creation of keys/certificates?

I am re-setting up some OpenVPN infrastructure to be more secure than the original and wanted some guidance. It's noted that the best security policy is to keep the Certificate Authority (CA) offline ...
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2answers
95 views

Does public key encryption/decryption speed actually matter?

There have been wars fought over RSA, DSA, and I'm sure other public key encryption algorithms, and usually the arguments are "Algorithm A is faster to encode, but algorithm B is faster to decode". ...
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1answer
68 views
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1answer
70 views

Are SSH keys and PGP keys the same thing?

I have a 3072 bit RSA key that I generated for use with SSH. Can this key-pair be used with PGP/GPG, or do I need to generate a new pair of keys separately for use in email encryption? Are the two ...
15
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4answers
2k views

Why should I sign data that's already encrypted? [duplicate]

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 ...