0
votes
1answer
28 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? ...
0
votes
1answer
44 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 ...
0
votes
2answers
48 views

ECDSA ciphers and forward secrecy question about key exchange

I have heard that with forward secrecy that the ECDSA ciphers generate different keys for "each session" because they are not dependent on the private key of the server. My question is how is "each ...
1
vote
2answers
57 views

Is there a secret-sharing public-key-encryption-based service? [closed]

I need to share some sensitive information with someone else who can only communicate via E-mail. I don't love the idea of sharing this information freely over email in plain text, so I was ...
0
votes
2answers
71 views

Encryption mechanism

I want to send data over the Internet securely. For that, I am using an public key of the receiver to encrypt the data. In this case, if an intruder in the network modifies the data, like placing the ...
1
vote
2answers
62 views

Public e-mail Encryption Certificate

I'm quite new to this, so don't be too hard on me. I'm currently using the CipherMail MTA to generate e-mail encryption certificates. I created an own CA and public and private keys for our contact ...
1
vote
3answers
162 views

Is storing the private key and public keys in same directory on server recommended, like OwnCloud does?

Is this recommended or a good/normal practice? I think not. Because I saw that OwnCloud stores all encryption keys in one directory on the server. One directory contains the private key(s) and one all ...
0
votes
0answers
24 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
vote
3answers
128 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
votes
1answer
79 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 ...
4
votes
1answer
78 views

Car Remote App Security

Car manufactures like BMW, Audi or Mercedes-Benz all provide mobile applications to control your car. All apps share really critical functions like remote lock/unlock or the ability to find your car ...
1
vote
1answer
45 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 ...
32
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 ...
1
vote
2answers
213 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, ...
1
vote
2answers
224 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 ...
1
vote
3answers
337 views

How does encryption/decryption work when one generate random key?

I am new to this and want to ask a basic question. Suppose I used my password (say "ABC123") to generate a key using the PBKDF2 algorithm (or any such algorithm). For encrypting a file I'll input my ...
1
vote
0answers
33 views

Message and Key Security

I'm reading Post-Quantum Cryptography, and in the page 106 in the beginning of the Section 3 it says: In this section we consider the message security (opposed to key security) of code-based ...
1
vote
3answers
146 views

Using public/private key without signed certificate

I am working on a java program and I am now working on its network security. I want to use a secure connection since it transfers a lot of sensitive information. On all security guides it is mentioned ...
1
vote
1answer
361 views

How to process or manage Key-Encryption-Key using HSM?

Let's consider two Encryption keys: 1.Data-Encryption-Key(DEK) 2.Key-Encryption-Key(KEK) KEK will be securely stored in HSM, which will be encrypted using master key. Data Encryption Key will be ...
1
vote
1answer
403 views

Which digest algorithm to use with creating a public/private key pair

I'm generating a Public/Private key pair in PHP with the following: <?php $config = array( "digest_alg" => "sha512", "private_key_bits" => 4096, "private_key_type" => ...
1
vote
2answers
185 views

Nested encryption for multiple users

I've developed a web application (developed in .NET MVC 4) which have multiple users with personal login credentials. The web application holds a lot of content uploaded by the users. My client would ...
3
votes
1answer
110 views

Can we build a key exchange protocol without certificates?

Assume that the server and the client both has some secret key K. Is it possible to have a key exchange protocol with authentication between them such that MITM attack cannot hold and if the key is ...
2
votes
5answers
428 views

Is asymmetric encryption vulnerable to man-in-the-middle attacks?

I'm looking for ways to send private messages over a public channel, and in doing this I stumbled in asymmetric encryption, which is just perfect for what I was looking for at first - A and B ...
3
votes
2answers
284 views

Totally secure public key distrubition

Public-key cryptography secures communications provided that you use pre-shared public-keys. The problem is how to share these public-keys while maintaining authenticity? How can we be sure that ...
23
votes
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 ...
6
votes
2answers
514 views

ECC based Client Certificate import in Chrome/Mozilla in windows

I have deployed a PKI server and successfully able to generate the ECC based user or client certificates. but non of the web browser support ECC as public key. I have tried different tools and also ...
3
votes
1answer
529 views

Can you make a digital signature using the receiver's public key?

My question is, can you make a digital signature using the receiver's public key and then have the receiver verify the signature using his private key? I always thought that in order to create a ...
5
votes
2answers
132 views

Is there a reason to encrypt an encryption key with a certificate before storing it?

Suppose my .Net application which is installed in the client encrypts a data. I want to use a different key generated randomly for each client so each client doesn't know the key of the other. Someone ...
3
votes
2answers
497 views

How safe is a PGP private key that has “escaped”, but without its password?

Assuming your PGP private key is protected with a password, and it "escapes", but the password does not, how worried should you be? Obviously in the real world, you would immediately revoke the key ...
2
votes
1answer
973 views

Are very short messages secure using Public Key Encryption? [duplicate]

Say Alice publishes her public key and then disappears from public view. Bob then needs to send a message to her that's either "OK" or ":(" so he takes her public key, encrypts his message and then ...
5
votes
1answer
2k views

What is the difference between Key Escrow and a Recovery Agent?

From what I understand Key Escrow is where a copy of they key is stored in a safe place so they can be recovered later. But in the context of PKI, a Recovery Agent can also recover private keys. How ...
8
votes
2answers
870 views

Is ECDSA breakable by quantum computers?

Is ECDSA secure from quantum computers? Will quantum computers be able to calculate it's private keys from the knowledge of the public key once there are working quantum computers?
3
votes
1answer
143 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 ...
1
vote
1answer
224 views

x509: must the signature algorithm and public key algorithm match?

I'm having trouble getting Firefox to send an encrypted message using a certificate, and I've found that the only difference between this one and others that work fine are that this one has a DSA ...
4
votes
1answer
721 views

Why is ECC more vulnerable than RSA in a post-quantum world?

Forgive me if this should be in the crypto sub, but sometimes the answers there are very mathematical and I would rather have an answer which is a bit lighter on the math but still strong on the tech ...
6
votes
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 ...
3
votes
2answers
628 views

How to secure a truecrypt container allowing access with multiple SSH public keys?

I would like to create a TrueCrypt container which can be accessed by multiple people. The container itself can be stored anywhere, e.g. in a shared folder in Dropbox or Google Drive, ... I would ...
1
vote
3answers
321 views

RSS Feeds: restrict access

"We are a bunch of journalists and we share much of the information via e-mails. This has become tedious now. Hence we found out a way to share, by just having to share our private blog posts via ...
2
votes
2answers
849 views

Difference between Encryption and Verification certificate

What is the difference between the Encryption certificate and Verification certificate in Outlook? When exchanging certs, it just requires a digitally-signed message to be sent. It seems as though ...
4
votes
1answer
149 views

Share or not share public key for servers?

In order to encrypt communications from our (custom) client to our (custom) servers our current scheme is a bit like this: Client uses the bundled public key A to encrypt some random key material. ...
4
votes
1answer
127 views

What physical, electronic, and software characteristics are important in a smart card?

I'm evaluating smart card readers to store a number of private keys, but don't know where to start. What criteria is important regarding smart cards and preventing the extraction or unauthorized used ...
3
votes
2answers
874 views

What hardware technology (GPU, FPGA) is fastest at generating RSA keys?

I'm interested in generating RSA keys in rapid succession and am looking for the correct hardware to so. I think what I'm looking for is very similar to a brute force attack on RSA keys, but my ...
3
votes
1answer
160 views

Can we use a public key scheme for performing cryptographic commitment

Is it possible to use a public key scheme such as DSA as a commitment scheme? Are there any problems with doing this?
2
votes
2answers
910 views

Key Exchange using PKI

I'm new to the field of cryptography and trying out a sample program to understand PKI key exchange mechanism. I tried creating a self signed certificate using openssl openssl req -x509 -nodes ...
1
vote
2answers
154 views

Certificate Security in intranet Environment?

We have this topology in our company : A new rule says that each document being sent by outlook should be encrypted. we decided using PGP. We already have a certificate ( self signed). the ...
4
votes
1answer
365 views

Is OpenPGP encryption a valid replacement for SSL when passing messages?

I am writing an application that occasionally needs to transmit larger messages to other servers on the internet without allowing people to snoop on the traffic. The normal way to handle this is to ...
3
votes
1answer
932 views

What are the Netscape Cert Type attributes? Why/when are they needed?

What are the Netscape Cert Type attributes in a X.509 Certificate and how are they different with the X509v3 extensions? Example: There is the Client/Server Extended Key Usage (X.509) but there is ...
5
votes
3answers
668 views

Digital Signature and Verification?

AFAIK , When Alice wants to write a message to Bob -- she uses Bob's public key and encrypt the message - and then Bob - using his private key - use to decrypt it. So public key is used to decrypt ...
6
votes
3answers
452 views

What risks would exist in transmitting an encrypted PKCS12 via Https

I have a scenario in which I would like to automate the deployment of client certificates generated by an issuer I control. The approach I am considering is given below, and I would appreciate ...
3
votes
1answer
145 views

CMC (RFC 5272) compatible CA server

I need a CA server or any tool that supports Certificate Management over CMS (CMC) format, described in RFC 5272 (RFC 2797). I need a possibility to generate different Full PKI requests and responses ...