Tagged Questions
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 ...
3
votes
1answer
120 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 ...
5
votes
3answers
350 views
Is a 512 bit RSA key secure when used temporary?
Is a 512 bit RSA key secure when a new key gets generated and used approximately once a week? The key is only used for signing messages, not for encrypting sensitive data.
This is for a system where ...
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
270 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 ...
1
vote
4answers
166 views
RSA and encrypted authentication
Symmetric algorithms such as AES provides modes such as GCM which can be used for authenticated encryption. Assuming that I'm using RSA instead of AES, does it still make sense to add authentication ...
2
votes
3answers
141 views
Given a large enough sampling of public keys could one begin to identify a private key?
For example, an ISP or government capable of tracking millions of keys being exchanged. Would that provide a sample large enough to be able to identify the private key on either end?
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?
3
votes
3answers
171 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 ...
0
votes
0answers
113 views
Encryption in Messaging/RAbbitMQ/SOA [closed]
I'm a student and now 2nd time poster, please excuse any lacking detail on my part.
For my exams I'm doing a cross-platorm application using RabbitMQ for messaging. It'll serve as POC for both SOA ...
2
votes
2answers
301 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 ...
8
votes
2answers
596 views
Are there really functioning quantum computers?
I saw this video on youtube on quantum computing. It says that a company called dwavesys has already made commercially available quantum computer. I checked on the website and it exists. I thought ...
2
votes
2answers
254 views
Revoked certificate validation using past times
I'm working on XAdES implementation for Java, as such I require cryptographic implementation to be able to verify certificates in the past.
Unfortunately I have problems verifying revoked ...
1
vote
0answers
131 views
Verifying Authenticode signed executables and DLLs using OpenSSL API [closed]
I have installed openssl and now the rsa_test.c is running fine. What I want to do is:
Open any exe or dll digital certificate. Extract the Thumbprint and PublicKey.
The public key contains the ...
5
votes
1answer
162 views
security issue on storing keys and certificate on token
I'm creating a sample USB token with Atmega64. As I have to store both the public and private key and the certificate on my token is there any important security issue that I should worry about, ...
3
votes
2answers
189 views
Distributed XAdES-X and XAdES-A signatures over multiple documents
As the standard is not completely clear in this matter, I'm trying to found out if the XAdES standard (ETSI TS 101 903 v1.4.2) describes distributed case in which the SigAndRefsTimeStamp element or ...
4
votes
1answer
56 views
Standards for CA cert revocation and time-constrained cryptographic algorithm parameters
I'm working on software that will be in use for foreseeable future (15 years+) that will need to validate XAdES-A signatures (long term archival, similar to PAdES-A, but for XML). That means, it will ...
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 ...
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
1answer
532 views
how do extended validation X.509 certs work?
https://www.forumatic.com/ uses an extended validation cert. wikipedia.org's entry on extended validation certs says that a cert is known to be an extended validation cert if the OID in the ...
1
vote
1answer
84 views
valid intermediate certs not in browser
Say an X.509 cert is signed by an intermediate cert that's not in your browser. Maybe the root certificate is but not the intermediate cert. At that point it seems like a valid certification path ...
7
votes
2answers
281 views
X.509 certificate policies question
I asked another question about certificate policy mappings. This is a different issue. This is about Certificate Policies.
To quote from the X.509 RFC:
In an end entity certificate, these ...
1
vote
1answer
205 views
X.509 certificate policy mapping question
So I'm a little confused how X.509 certificate policy mappings work. So let's say the following depicts my cert chain:
root CA ---> intermediary CA ---> client cert
Would the root CA have a ...
5
votes
3answers
849 views
Why does OpenVPN require securely sharing certs with clients?
The ubuntu docs on OpenVPN have this part in the instructions:
Copy the following files to the client:
/etc/openvpn/ca.crt
/etc/openvpn/easy-rsa/keys/hostname.crt
...
3
votes
3answers
223 views
Public key system confusion
I read the following about PKI:
Using a public key system, a user may encrypt a portion of a document
using his or her private key. This message will later be decrypted by
the recipient using ...
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
...
8
votes
3answers
2k views
What are the risks of self signing a certificate for SSL
Let's say I sign a SSL certificate for myself, and I'm not using a certified CA. What are the risks and/or threats of doing it?
12
votes
4answers
3k views
how digital signature verification process works
I am not able to understand that how the digital signature is verified. I know that digital signature will be attached to the message and sent by sender to receiver. then receiver uses the public key ...
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?
6
votes
3answers
147 views
Guarding against rogue certificates
There has been a lot of news recently about certificates being falsely issued (due to the issuing authority having poor system security!). Apparently the targeted users were mostly Iranians, but it's ...
5
votes
4answers
4k views
Recommendations for a Certificate Management tool for Linux
A client is looking to roll out OpenVPN to all its mobile employees and will use certificates on both the server and all clients.
This creates a new challenge to manage all these certificates and ...
6
votes
3answers
314 views
Why are CA's signing keys available on the internet
I am not very knowledgeable about CA certificates, but I thought these things mainly said
"The public key for bank X is Y, and this is verified by CA Z".
Once you've bought this certificate, there is ...
9
votes
3answers
399 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 ...
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 ...
3
votes
1answer
338 views
What kind of certificate do I need to be able to make and sign my own digital signing certicates?
At build time for a program, I would like to generate a new key pair, and create a certificate that will be embedded (securely) into the program. The purpose of the key pair is to digitally sign an ...
6
votes
2answers
223 views
Geographic equivilent of RFC 3161 (X.509 PKI Time-stamp Protocol)
First time poster here, hope to be around more often.
I'm in need of a cryptographically secure 'stamping' system that allows not only time but also location to be attached to data, while still ...
12
votes
3answers
1k views
What happens when an Intermediate CA is revoked?
Currently I'm working on a certificate manager that allows our product to securely (over TLS/SSL) connect to remote webservices.
For security, we use CRL-checking to find out if a certain certificate ...
10
votes
4answers
648 views
Why isn't OCSP required by default in browsers?
According to the following screenshot, taken from firefox-3.6.17-1.fc14.i686, Firefox has an option to fail closed when unable to connect to OCSP servers.
Can someone please explain why this isn't ...
6
votes
2answers
371 views
security of PKI, Certificates, certificate authorities, forward secrecy
I want to understand how certificates add to the security of information exchange.
Suppose i have a encrypted bidirectional connection between Alice and Bob, using a public key/private key pair. As ...
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 ...
7
votes
1answer
540 views
Moving from a one tier to a two tier Microsoft Certificate Authority hierachy
Right now we have a single Microsoft Enterprise Root CA which issues certificates to our VPN users for two factor authentication. We're planning to extend use of the CA to issue certificates for RDP ...
7
votes
1answer
952 views
Renewing Microsoft Certificate Services Root Certificate
We currently have Microsoft Enterprise Certificate Server installed on a domain member machine which issues 1 year certificates to users for authenticating to VPN.
We'd like to start issuing web ...
11
votes
1answer
667 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
...
7
votes
3answers
1k views
Certificate authorities for a PKI
Some people think the certificate authorities for a PKI should be the government, but others think certificate authorities should be private entities, such as banks, corporations, or schools. What are ...
6
votes
3answers
188 views
Renew digital certificate
If I have deployed a digital certificate on a webserver and if it needs to be renewed then what steps do I need to follow? Will I need to generate a new longer public key private key pair? Why do ...
6
votes
3answers
922 views
Certificate chain
For my computer to verify the identity of a certain certificate should it have all the certificates up to the root certificate?
8
votes
2answers
2k views
SSL Certificate revocation check
In the SSL protocol I don't see where the certificate is checked for revocation status.
https://developer.mozilla.org/en/Introduction_to_SSL
Is the Certificate Revocation and Status Checking not ...
1
vote
2answers
1k views
What is an intermediate certificate authority?
What is meant by an "intermediate certificate authority?"
11
votes
2answers
2k views
How does RSA encryption compare to PGP?
On this answer ck says
RSA and PGP are different.
What you are essentially asking is how
do I run my petrol car on diesel? The
answer is you can't.
I would be interested in a more ...
