Tagged Questions

3
votes
2answers
108 views

what is the difference between a mac and a digital signiture

I understand that a MAC algorithm takes a message and a private key as input and hashes them to a value. I understand that senders and receivers often use MACs to authenticate a message and check the ...
4
votes
2answers
721 views

When using symmetric key encryption, do we need to sign?

Say we're using a shared key between two parties, that has been distributed using public key encryption, is it still necessary to sign any data that's encrypted using the shared key? Or is it enough ...
12
votes
2answers
325 views

Which factors should I consider for devices that accept handwritten digital signatures?

These days many locations ask you to give your signature on a digital signature pad/device. As I am situated in Europe, the EU directive 1999/93/EC seems to regulate it. From what I have found out ...
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 ...
1
vote
2answers
337 views

Signed request vs HTTP digest auth for API authentication?

By signed request I mean something like this (simplified example): Client creates a sig in his request: $sig = hash('sha256', $api_key.$data); which generates 7409ur0k0asidjko2j for example. He then ...
0
votes
1answer
95 views

Can I export my digital certificate to this emtec usb

It is said here http://www.emtec-international.com/sites/default/files/s530_aes_en_0.pdf 2048 bit RSA module: ready for PKI application SHA256 data hashing: ready for digital signature Does it ...
0
votes
1answer
318 views

DRY API Authentication Design Between Services

I am creating an API service that is going to require authentication. this will be the first part of a project that will include a front-end service for my website, and also open up the api for 3rd ...
5
votes
1answer
280 views

OpenPGP Encryption / Decryption Process Using GnuPG

I want to know if my method of encryption can ensure the security of my data if my database was hacked as well as the authenticity of the data I am decrypting. I am using GnuPG's implementation of the ...
5
votes
3answers
239 views

DHE exchange and client authentication

If a server has a known public key and a Diffie-Helman exchange is performed and signed by that key, is there any benefit to authenticating the client before establishing a secure channel instead of ...
4
votes
3answers
561 views

Is there a way to accept signed requests without storing client's password in plaintext?

We are developing REST Web service. We will give Identifier and Secret string to each of our REST clients. When doing requests, clients will authenticate themselves using HMAC algorithm (they will ...
21
votes
4answers
5k views

How to achieve non-repudiation?

If I have a message that I need to send to another person, how do I achieve non repudiation ? Is digitally signing the message sufficient ?
5
votes
2answers
1k views

Dealing with expired or revoked signing certificates with Infopath documents

Suppose I have an Infopath form that is digitally signed today by a valid, and active user. When that user leaves the company, we disable the account and revoke the certificate. This causes a problem ...