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1

You should HMAC the payload as well. Since you mentioned including a header with the HMAC of the path and query parameters, you could have a separate header that contains the HMAC of the body. However, you will likely only want one HMAC to be sent, so an attacker couldn't mix and match the different sections. Thus you could do something like this: ...


1

No, it isn't secure. Signing a application does only provide traceability and unmodifiability - the created application can be traced back to the person who signed it, and the application cannot be modified without invalidating the signature. Anyone who has the Money and possibility to go through the process of getting a code signing certificate will get ...


1

I think that an HMAC provides little added security if the session ID is something that is hard to guess. For example, a long secure PRNG. But if the session ID is simple to guess then there is the risk of session hijacking. As the expressjs framework allows you to provide a session ID creation function that returns IDs with unknown security properties, an ...


22

Certificates are signed and the cryptographic signature is verified; if the signature matches then the certificate contents are exactly as they were when the certificate was signed. This, of course, does not solve the problem, it merely moves it around. The complete structure is called a PKI. The certificates which are preinstalled in your computer (came ...


6

If a virus installs a new root certificate on your computer, and a spoofed website presents you with a certificate with a valid signature chain from that root certificate, then your computer will accept it as a valid certificate. But this shouldn't be seen as a problem with SSL/TLS -- if you have a virus with that level of access, then there are lots of ways ...


6

The message digest is a hash of the original message. You can't reconstruct the message from the digest. Bob computes the digest and compares it to the one Alice sent him. If it matches, Bob knows that the message hasn't been changed, since any change in the message will cause a change in the digest. He also knows that the message came from Alice, ...


1

It's really pretty much irrelevant. Message digests are done using a preimage-resistant hashing algorithm, which means that knowing the hash doesn't help you find anything that hashes to that value faster than brute force. But the attacker could also do the brute-force attack directly on the signature -- with both RSA and DSA, an attacker can see if the ...


1

Authentication, Integrity (?) and non-repudiation are digital infosec terms, and what you want are the electronic terms. Are you in the United States? The American Bar Association has extensive guidance on this. Try Digital Signature Guidelines: Legal Infrastructure for Certification Authorities and Secure Electronic Commerce for some basic information ...


1

You shouldn't use the recovery partition even if it's signed. I would personally be more worried about the manufacturer than the person who's selling it to me (and if the seller is really malicious, he would've embedded some evil hardware keyloggers rather than relying on a partition I may never ever use). To strictly answer your question, I believe the ...


1

This link gives a pretty good explanation. In particular, this section talks about how to verify packages. In a nutshell when you install packages your system check that they are signed with a known key, using public key crypto. This guarantees that the packages come from a "trusted" source. In your case some packages were signed with an unknown key and you ...



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