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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1answer
56 views

Resign root CA as SUB?

Imagine I have a Microsoft root offline ca running since half year, but suddenly I want to include it in my company hierarchy, resigning it with the company official root, But I need both continue ...
2
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3answers
179 views

Are there commercially available hardware encryption devices over USB? [closed]

I'm designing a system where some combination of hardware and software (lets call it an appliance...) sends asynchronous secure archival to the cloud. By secure, I mean, AES-256 encrypted, with AES ...
0
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1answer
320 views

ECC Public Key length differs from bit representation

A 256 Bit ECC key-pair (256 Bit is supposed to be the length of the public key) generated with OpenSSL using this command from the manual: openssl ecparam -name secp256k1 -genkey -noout -out key.pem ...
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0answers
26 views

How digital certificate works? [duplicate]

I am trying to understand the digital certificate concept , but I am confused , Below goes my understanding & question, We are using Digital certificate because if Bob & Alice share their ...
1
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1answer
105 views

Certificate pinning in a browser

I am trying to understand certificate pinning. Google started adding a whitelist of CA certs that they use for their certificates and if a cert for a google service is issued outside of this list ...
2
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3answers
104 views

How are public key certificates updated securely?

Let's say I get a new computer that's never been connected to the internet before. The first time I connect it to the internet, is it susceptible to a mitm attack while downloading its public key ...
2
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2answers
245 views

Certificate authority structure - best practices

I'm working for a company that sells software products to customers some of which do not have the resources and/or know-how to build and maintain their own CA (used for the SSL communication of our ...
0
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2answers
111 views

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 ...
6
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1answer
668 views

What's keeping a malicious man in the middle server from forging a valid certificate

According to process of authenticating a server certificate: What's keeping a malicious server to fill up a valid server certificate since it knows all the things: Forged Server public key (man ...
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3answers
123 views

Where do my keys come from for requests over SSL? [duplicate]

From what I understand, when you send information to a website over SSL, you encrypt the information you send with their public key. However, if you want to be able to decrypt the information they ...
3
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1answer
71 views

Utility of multiple signing subkeys when we're restricted to a single encryption subkey in GnuPG (PGP)

As I understand it, GnuPG allows the creation of multiple subkeys, but multiple encryption subkeys are problematic because it's not clear which encryption subkey someone should use when sending a ...
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1answer
270 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 ...
2
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2answers
2k views

Public keys on OpenSSL vs PGP?

It is my understanding that PGP permits multiple public keys, and in SSL you can only extract one public key? Is this correct? Is there any brief high level run down between the two. I don't feel as ...
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2answers
83 views

Could a network host and process programs while securing against piracy?

Consider an ideal service hosting network, which: Lets programmers: Publish a program in such a way that it can't be retrieved. Associate a program with a wallet. Specify a cost per request and ...
3
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3answers
105 views

What benefit is there to adding a password to your SSH key?

If you run the following command on a Linux/Unix machine, among other things, you get a prompt for a password: $ ssh-keygen -t dsa Enter passphrase (empty for no passphrase): What does adding a ...
3
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1answer
153 views

Clarification on Digital Certificates

I used the makecert tool to create: self-signed certificate client certificate These are the commands I used: makecert -n "CN=MatthewCA" -r -sv MatthewCA.pvk MatthewCA.cer **for self signed ...
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2answers
334 views

Why is there no Domain CA?

I was asked to deliver a signed SSL certificate for an IIS server for a client. I have previously done this for the same client/domain before, so it start to seem like an unnecessary expense to hold ...
0
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0answers
37 views

Breaking public key pinning

I was reading through the IETF's Public Key Pinning Extension for HTTP (http://tools.ietf.org/html/draft-ietf-websec-key-pinning-12). The acknowledgements section has the following: Thanks to Trevor ...
0
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0answers
27 views

Looking for OpenSC compatibile token

I am currently proud user of Feitan ePass2003 with OpenSC, however it is not 100% reliable on Windows, on Linux it's just perfect. Anyway I started to looking and I have two candidates eToken Pro 64K ...
0
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4answers
147 views

Can a certification authority sign another CA's certs?

Disclaimer: I have low knowledge of X.509 and PKI, so I would appreciate an answer that is not entirely technical, i.e. by using real-life example scenarios.) I was searching for information ...
0
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1answer
83 views

Public Key Authentication

Is there another way to verify someones public key without a CA signing it? A challenge-response authentication including some sort of UID of the smartphone? Smartphone A generates asymmetric key ...
9
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2answers
2k views

Why do PGP master keys only have a single subkey, and tie certification with signing by default?

After learning more about PGP subkeys and how to split apart the roles of (S)igning, (E)ncryption, (A)uthentication and (C)ertification, I discovered that in most cases(?) a default master key has a ...
1
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1answer
214 views

OAuth and public keys

I'm trying to wrap my head around the whole concept of public keys and Oauth. I get the basic Oauth and PKI flow and the different actors involved but I'm still unsure how public/private keys play a ...
56
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7answers
40k views

Certificate based authentication vs Username and Password authentication

What are the advantages and drawbacks of the certificate based authentication over username and password authentication? I know some, but I would appreciate a structured and detailed answer. UPDATE ...
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1answer
225 views

How to become an internationally recognized certificate authority (CA)?

What's the procedure a certificate authority (CA) must follow to get internationally recognized, like Verisign or GlobalSign?
2
votes
2answers
188 views

What happens if the CA has knowledge of private keys?

In a classic PKI scenario, the certificate authority receives signing requests generated by an end-user which owns the keychain, and thus has his private key secret. Consider a scenario in which the ...
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2answers
8k views

How to get public key of a secure webpage?

How can I get the public key of a webpage like verisign , etc. using HTTPS protocol?
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6answers
2k views

Should I hash a password if it is randomly generated

The best practice is we should hash a user password using algorithms such as bcrpyt to protect the user, however, given the following conditions, is hashing in the backend still matters? the ...
1
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1answer
69 views

When does S/MIME require the other party's certificate and when is their key enough?

Trying to understand S/MIME implementation, I see that sometimes you must have the other party's certificate, and sometimes its enough to just have their public key. I'm confused as to when you need ...
2
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1answer
316 views

OpenVPN seamless migration from 1024-bit RSA to 2048-bit RSA keys

The company I work for has a few OpenVPN servers used by over 200 employees. The servers were deployed a few years ago using the default easyrsa settings and now we want to upgrade to stronger ...
4
votes
3answers
681 views

Why are SSL certificates valid only from a certain date?

Each SSL certificate is valid starting from a specific date and up to the expiration date. What's the point in that "valid from" date? Why do we want a certificate to only be valid after a specific ...
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3answers
124 views

Detect message tampering without shared key and without certificate authority

Is it possible to detect if a message has been tampered with, without using MAC (i.e. shared key) and without using a "trusted" third party (i.e. certificate authority)? I'm pretty sure it's not, but ...
0
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1answer
83 views

list of PKCS7 certificate file extensions

RSA (the company) devises and publishes the public key cryptography standards. In those standards PKCS #7 is a standard which defines how to encrypt and sign messages using PKI. PKCS#7 defines a ...
3
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1answer
217 views

Heartbleed - is this scenario possible? how bad would it be?

Let's make the following assumptions: A trusted root certificate was being served with a vulnerable version of OpenSSL. Prior to public disclosure, a malicious entity was aware of and exploited the ...
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3answers
427 views

Can a smart card with PKI certificate be used to protect a document?

I want to use a smart card (or USB cryptotoken) with a PKI certificate for manual authorisation. Is this possible? I want to put a file (e.g. a word file or even a simple text file) into a smart ...
1
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2answers
104 views

Where to find or purchase non-SSL certificates

I hope this is the right stackexchange - if not, please advise. As to the actual question: have a system we've developed that makes heavy use of asymmetric cryptography in various different ways ...
0
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1answer
283 views

Trusted Certificate Authorities - how do they work?

microsoft.com for example can use a Verisign Certificate for their domain. What are the chances that an attacker could ask verisign for a m1crosoft.com domain and get approved? It is very simillar, ...
4
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1answer
412 views

WebRTC P2P SSL - Where are the keys generated?

My understanding is that with the WebRTC peer-to-peer data API, communications between peers are encrypted via a modified form of SSL. Where are the keys for the peer-to-peer SSL connection generated, ...
33
votes
7answers
4k views

How dangerous might be publishing a public key?

Maybe this question sounds obvious, but I wonder how dangerous might be publishing a public key for an asymmetric encryption system? I know public keys are meant for encrypting messages by anyone ...
23
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5answers
3k views

Why is Bruce Schneier recommending symmetric crypto over public key crypto

I just read the article written by Bruce Schneier, the crypto guru. In the article, he says : Prefer symmetric cryptography over public-key cryptography. But, he doesn't shed any light as to ...
0
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1answer
716 views

Can I ensure that a public key derived from a private key is unique?

In asymmetric cryptography, is it possible to ensure that public key derived from a given private key is unique, no matter the algorithm?
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4answers
1k 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 ...
4
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1answer
133 views

Public keys without the certificates

There are two clients and a server. Each client generates an RSA key pair and uploads public key to the server. The server associates the public key with the user identifier that is specified during ...
0
votes
4answers
90 views

Is it ok to send user's private key away, even if protected with a SSL channel? [duplicate]

I'm developing a webserver that performs digital signatures of (xml, pdf and office) documents and then validates those signatures. My idea is: an user puts its SmartCard and through a PIN, he gets ...
0
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1answer
401 views

Possible to Derive Private Key from Public Key Given Enough Computing Power? [closed]

Is it possible via brute force to derive a private key from a public key (such as a website's SSL certificate)? If so, how much computing power would you need to make it feasible, compared to say, ...
1
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2answers
370 views

SSL/TLS : Authentication mechanism

I have these doubts regarding authentication in SSL/TLS : Will there be an authentication involved for all SSL connections ? For eg. when I browse the internet, using the most up-to-date browser, ...
2
votes
2answers
285 views

How to maintain security and trust with a PGP keypair for a team or group of people?

I've seen many instances where a company or organization generates and uses a PGP keypair for a team or group of people. Most likely they all have a copy of the private and public keys on their ...
0
votes
2answers
139 views

Achieving PFS with public key cryptography

I'm seeking to understand how Perfect Forward Secrecy (PFS) works for non SSL applications. More specifically, I'm interested in how Moxie Marlinspike accomplishes this in TextSecure and other ...
3
votes
3answers
259 views

Why do you need to encrypt symmetric key?

I'm reading this pki article and as you can see near the bottom, the quick animation and description: The sending computer encrypts the document with a symmetric key, then encrypts the symmetric ...
0
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1answer
34 views

OID for creation date/time (X509 certifcate field)

X509 certificates used in PKI{X} have notBefore and notAfter dates. I'd like to stamp a certifcate with a creation stamp, and the stamp is distinct from notBefore and notAfter. Is there an OID for a ...