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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Get the Signature algorithm from a public key? [closed]

When I do PublicKey.getAlgorithm(), it only returns me RSA. Am looking for something to return Sha1RSA. Basically to identify if it is a sha1 or sha2 algorithm. Any help is appreciated. Thanks,
1
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1answer
160 views

Authenticated Diffie Hellman Key Exchange

It appears that the textbook version of Diffie-Hellman is susceptible to man in the middle attack and the use of digital signatures could prevent this attack from occurring. Digital signatures could ...
1
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1answer
64 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 ...
4
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3answers
214 views

Anonymiszing sensitive data in MySQL DB while retaining searchability [closed]

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 ...
2
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1answer
288 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, ...
4
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1answer
90 views

How long do 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Do GPG/PGP keyservers "garbage collect" old keys which have expired, been revoked, or simply haven't been updated in a decade?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 ...
1
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1answer
49 views

How to understand socat certificate check limitation?

I have set up a certificate-based connection with socat using this tutorial: http://www.dest-unreach.org/socat/doc/socat-openssltunnel.html My socat connection works as following (only the relevant ...
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1answer
85 views

How is PKI used to encrypt an e-mail for multiple recipients?

My understanding is that when an e-mail is encrypted and sent to a recipient, the recipient's public key is used to encrypt the e-mail, and then only the recipient can decrypt it with their private ...
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1answer
237 views

How can the private key be obtained in PKI without alerting a third party? [closed]

For example, I sent a message to Ardi and encrypted it with Ardi's public key. Ardi must decrypt the message with his private key. How can Ardi's private key be obtained in PKI without anyone else ...
2
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2answers
92 views

Distributing public keys; with or without a sub-key?

Most of the public keys I am getting from friends have a sub key in addition to the pub key. For educational purposes I retrieved some public keys and came across this Linus Torvalds' key that does ...
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1answer
160 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 ...
0
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1answer
379 views

Shall I set “RSAAuthentication yes” in sshd_config if I use only ECDSA key?

In a context of proprietary client boxes and servers, I want to limit authentication to ECDSA keys. Historically, "RSAAuthentication yes" was used to enable authentication with RSA and maybe DSA keys. ...
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2answers
4k views

Is your PGP passphrase used to decrypt an encrypted private key, or needed in conjunction with the private key to decrypt the message?

If the former, then if the private key can be used to digitally sign messages, why doesn't your client offer to encrypt this highly sensitive piece of data? If the latter, then if someone had access ...
5
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1answer
2k 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 ...
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2answers
142 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 ...
1
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1answer
76 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 ...
0
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1answer
128 views

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

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 ...
3
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2answers
3k 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 ...
3
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3answers
198 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 ...
0
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0answers
48 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 ...
1
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1answer
80 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 ...
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2answers
150 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 ...
4
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1answer
166 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 ...
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5answers
184 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 ...
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1answer
226 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
178 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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2answers
110 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 ...
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2answers
211 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 ...
2
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2answers
140 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 ...
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2answers
127 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
174 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
1k 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 ...
2
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2answers
2k 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
79 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 ...
0
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1answer
96 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 ...
3
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1answer
377 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 ...
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2answers
120 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 ...
10
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3answers
2k 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, ...
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0answers
54 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
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1answer
208 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
122 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
291 views
1
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1answer
161 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 ...
0
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1answer
58 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? ...
7
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2answers
406 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 ...
0
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1answer
564 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 ...
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5answers
1k 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 ...
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0answers
104 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 ...