Tagged Questions

3
votes
1answer
46 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 ...
6
votes
2answers
202 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
51 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
77 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
150 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 ...
3
votes
1answer
124 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 ...
2
votes
2answers
168 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
110 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 ...
1
vote
2answers
191 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
90 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. ...
3
votes
1answer
70 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 ...
0
votes
0answers
81 views

What McEliece key size can provide standard security today? [closed]

i don't wanna use RSA because it will be plaintext very soon but we can't stop using internet to send private data. Does McEliece cryptosystem provide security today ? What McEliece key size is ...
2
votes
2answers
272 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
96 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
304 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
94 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
112 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
150 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
237 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
173 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
60 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 ...
1
vote
3answers
306 views

Please recommend best-practices documents for sharing encrypted data with non-technical end-users

Is there one, or several, "best practices" documents which cover in clear simple language how to share data among a non-technical support staff and non-technical end-users at various organizations? ...
2
votes
1answer
232 views

Is the Netscape SMIME extension still required in a certificate?

Every Windows 7 host has a Trusted Root certificate from Entrust that has the "Netscape Cert Type" extension (see image) I'm comparing inter-operable S/MIME extensions and see a pretty diverse set ...
1
vote
2answers
98 views

S/MIME and Dual-use certificates

My assumption is that S/MIME almost always utilizes certificates as follows: My certificate can be used to allow people to encrypt messages and send them to me. My certificate (the same ...
6
votes
1answer
1k views

How does adding a random serial number improve a certificates' security?

This article says: "Finding collisions is a tricky process, since it requires you to muck with the bits of the public key embedded in the certificate (see this paper for more details). Also, ...
8
votes
2answers
3k views

Checklist on building an Offline Root & Intermediate Certificate Authority (CA)

Microsoft allows a CA to use Cryptography Next Generation (CNG) and advises of incompatibility issues for clients that do not support this suite. Here is an image of the default cryptography settings ...
2
votes
1answer
1k 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 ...
3
votes
2answers
436 views

What encryption schemes require two or 3 private keys to read a message?

I would like to encrypt some data so that it can only be read if two or three people use a private secret to decrypt the data. What is the best / most modern way to accomplish multi-person ...
8
votes
3answers
560 views

Is it safe to store a single symmetric key encrypted with several different RSA public keys?

For the field-based encryption of a database containing sensitive information, I was thinking of the following design: Every user has a smartcard used for client certificate login. After login the ...
2
votes
3answers
513 views

How can I share files with other individuals in the cloud in a secure way?

I would like to us a dropbox because it is easy and convenient. But I want to encrypt the files with the public key of the intended recipient, so he will be the only one who can access the data in ...
0
votes
1answer
250 views

Enterprise Encryption Considerations

What are the different aspects to consider for Enterprise Encryption policy? So far the resources I have are: https://www.owasp.org/index.php/Cryptographic_Storage_Cheat_Sheet ...
16
votes
4answers
4k views

How does PGP differ from S/MIME?

Is S/MIME an abstracted system for general MIME type encryption, whereas PGP is more for email? Why would I want to choose one over the other, or can I use both at the same time?
4
votes
2answers
235 views

How are possible uses for X.509 (SSL) certificates denoted?

X.509 certificates can be used for servers, clients, email, code signing and more applications. http://twitpic.com/6gdxaq indicates that a certificate can have different of these 'capabilities' on it ...
8
votes
3answers
483 views

Does the SSL encryption strength of a website really matter?

When looking to get an SSL certificate one is presented with a lot of options. For example lets take Network Solutions since they have a nice comparison chart. Immediately there seems to be 4 major ...
10
votes
3answers
1k views

Computationally simple, lightweight replacement for SSL/TLS

Target hardware is a rather low-powered MCU (ARM Cortex-M3 @72MHz, with just about 64KB SRAM and 256KB flash), so walking the thin line here. My board does have ethernet, and I will eventually get ...
11
votes
1answer
669 views

How would I implement “Broadcast Encryption”?

I have a stream that I want to encrypt for broadcast to 10,000 subscribers. I know I should encrypt this data using a symmetric key; and also intend that this symmetric key will be rotated every 30 ...
12
votes
2answers
357 views

Encryption and the “security time decay” of prior encrypted data

This question is on the assumption that any data once encrypted, may (eventually) be decrypted through Brute force (compute power/time) Exploits in the cryptography used Theft of private keys ...
6
votes
3answers
666 views

Safe implementation of sharing encryption secrets (username, password) in the cloud

I'm building a multi-tenant (cloud) environment that needs to push out (or make available for download) configuration files for agents (background services) that receive this information. One of the ...
6
votes
4answers
685 views

What kinds of SSL certificates are usable for encryption?

I know that Verizon SSL certificates cost close to $600. There are couple of cheap alternatives, but I never really understood why Verizon does not offer such certificates. Look for RapidSSL at ...