Collaborate Disseminate
I am trying to understand some concepts such as DH problem and its variants. I have the following question from the book I read. (note that I translated the question from my language to english)
Assume that two parties are using DH to mak… Continue reading which DH protocol is safer in communication with given condition? [migrated]
I’ve been reading lately about the Double Ratchet protocol, how it works conceptually. I understand generally the idea behind the protocol, that it provides Forward Secrecy and Post-Compromise security (the healing period depending on how … Continue reading Benefits of the Double Ratchet protocol over the constant Ephemeral DH key exchange
I came across a packet capture in Wireshark where p length = 257 bytes and pubkey length = 256 bytes. See the ServerKeyExchange snip below:
Diffie-Hellman Server Params
p Length: 257
p: 00a81c7b6633732007ba19bf733fc5f6cf5d0c9f8e03e… Continue reading DHE key exchange with p value 257 bytes but a pubkey of 256 bytes
We have received a vulnerability report where these values should be increased to 2048.
Can you please help me on this?
Continue reading Does Windows 7 support DHE/0ECDHE? [closed]
When I try to connect to the site https://api-mte.itespp.org with OpenSSL (openssl s_client -connect api-mte.itespp.org:443 -brief), it complains that the DH key is too small. But when I analyze its certificate, it says the RSA key is 2048… Continue reading Why do I get the error "dh key too small" when the RSA key is 2048 bits?
I understand that in a non-authenticated Diffie-Hellman setup, a man-in-the-middle attack can occur. Now i’m curious about the feasibility of the following scenario:
Let’s assume a situation where www.example.com exclusively supports authe… Continue reading Evading authenticated diffie hellman with MITM
The Dutch National Cyber Security Centre publishes advice for TLS configuration. Their latest guidelines can be found on their website.
One of the points in their latest guidline is that ffdhe2048 parameters should be phased out and replac… Continue reading Which clients do not support 3072 bits DH parameters [closed]
With Fido2 becoming more popular we see more and more affordable Fido2 hardware security keys on the market.
Can we use those tokens also for establishing a shared secret between two tokens?
I would like to use them to perform something si… Continue reading Can Fido2 hardware tokens be used for key agreement or Diffie-Hellman?
I have discovered that Diffie Hellman(DH)shared key is unequal in Apple Numbers, Google Sheets, and Mac Excel (2008).
In Section 1.0, the first try at a solution uses a small Prime to produce certain ranges in the above applications where … Continue reading What are the ranges of values for DH parameter a and DH parameter b [closed]
When ephemeral Diffie-Hellman (DHE) is used with TLS, the key-exchange key can/will be discarded after a key-exchange. right?
Is there good reason to use HSM for generating and storing DHE key, when the block cipher key is still stored in … Continue reading Does saving of ECDHE keypairs to HSM increase security of TLS?