Tag Info

New answers tagged

1

Diti is almost right about the historical context, but the real historical reason is in the part he/she omitted. For quite some time, gpg used DSA keys by default, which can only be used for signing, and then had to attach an elGamal subkey (which can be used for encryption only) to get a fully functional key. For RSA, that isn't necessary, but it was kept ...


2

Owner and Signature Trust Signature trust means a user puts trust into the identity of another user. If Alice signs (or certifies, which is the term I will use from now on for signing other's keys) Bob's key, she declares (following whatever rules) she puts trust in his identity. These certifications are usually publicly available on the key servers. You ...


0

The Debian RNG/DSA flaw actually did exactly allow to do this. If you use bad random numbers (eg., out of a small range as happened in the Debian flaw) the private key can be calculated out of the signature (by brute-forcing through all possible random numbers). sesse.net has a nice explanation of how it works exactly. So, use a bad random number generator ...


4

You can sign with both PGP and S/MIME. Contrary to Oliver Schmidt's response, it is possible to create an external signature using PGP (you can sign any file with a PGP key, not just text - a executable (.exe) is not a good candidate for inline signatures). This is referred to as "PGP/MIME". An external signature on a PGP file will be *.sig and S/MIME will ...


4

To make a long story short: Yes, that will work and it will make sense, too. I'll try to explain this: PGP stores the signature inside the email body. The body of a PGP-signed mail usually begins with -----BEGIN PGP SIGNED MESSAGE-----, followed by the hash algorithm and the message clear text, followed by -----BEGIN PGP SIGNATURE-----, followed by ...


0

Yes it is possible. Consider: signature = sign_message(message, private_key) // super secret sneaky private key theft signature = signature + "/" + base64(private_key) signed_message = embed_signature(message, signature) If you want the signature to still validatewith standard gpg --verify, you can alternatively use a Comment or MessageID signature ...


3

As I understand the scheme, you now have three pairs of keys: A Master public/private, and two Subkey public/private pairs. Please correct me if I misunderstood. According to https://wiki.debian.org/Subkeys , it seems like you should publish both of your public subkeys in order for others to both encrypt messages meant only for you, and verify your ...


5

You can't necessarily tell who can decrypt a given GPG file by looking at it, but assuming nobody has any knowledge aside from their own private keys and the encrypted file itself, it is possible tell how many people can. When you encrypt a message, GPG generates a random symmetric key, called a "session key", and uses it to encrypt the message. It then ...


1

This is not actually the secret key, but a kind of stub referencing the one on your card. This stub contains pretty much all "metadata" of your private key (including the public key belonging to it), but the actual private key is only stored on your card (and never leaves it). This is important, as the card only stores the actual key (and performs basic ...


1

OpenSSH As of version 6.5 OpenSSH offers a new private key format that supports the bcrypt KDF. The new format can be enforced by passing the -o flag to ssh-keygen. The number of KDF rounds can be customized with the -a flag. $ ssh-keygen -o -a 1000 References: ssh-keygen man page and Ted Unangst' blog. GPG I couldn't find anything equivalent to the ...


1

In practice: No, you need to make sure many other elements of the network aren't fooling you. I will concentrate on the transmission here. First, you want to make sure, you can contact the right recipient’s server. To do that, your sending mail servers does a DNS-Lookup for the MX-Record of the domain. Then the resulting FQDN has to be resolved to get an ...



Top 50 recent answers are included