All Questions
Tagged with transport-security diffie-hellman
12 questions
0
votes
1
answer
70
views
Is ECDH still secure if I embed the server public key?
I'm pretty new to the concept of key exchange.
Diffie-Hellman does not have authentication, so it makes no guarantees on who is the other party of the connection.
Both key pairs (client/server) need ...
- 103
0
votes
0
answers
29
views
Signal's X3DH Protocol - what is Alice's ephemeral key? Is the previous ephemeral key used in the next message's run? Are one-time prekeys signed?
In the Signal Protocol and X3DH Protocol:
https://signal.org/docs/specifications/x3dh/
I have a few questions:
1. In section 3.3. "Sending the initial message", it says:
Alice verifies the ...
1
vote
0
answers
69
views
secure channel for sending partial private keys!
In certificateless cryptography, the KGC must ensure that the partial private keys are delivered securely to the correct entities.
So my question is how KGC can send these keys secretly?
In the other ...
- 31
1
vote
2
answers
163
views
Is this self algorithm made private key for Diffie-Hellman key exchange secure
i created a function in javascript that creates my a for the DH exchange like this:
...
0
votes
0
answers
98
views
Interactive ECDHE Authentication With Numeric Code
Trying to simplify my question, keeping only core concepts.
Proposed solution:
Both user devices generates ECDHE key pairs. Send pub keys to each other. Generate shared secret.
Device that requests ...
1
vote
1
answer
91
views
Secure Communication
Focus:
I have to design a secure keep alive communication protocol and was wondering if it was necessary to sign the ciphertext after the session key has been generated as an attacker will not know ...
- 13
1
vote
1
answer
3k
views
What is Perfect forward secrecy?
I have read that when a user contacts an entity like a bank, it creates a pre-master key and then selects a master key for subsequent communications.
Can the lack of PFS, create a security flaw if ...
- 247
4
votes
2
answers
1k
views
Signal Double Ratchet - How can Alice send 2+ messages in the beginning of the Signal Protocol?
I'm studying about Signal Protocol and I had a doubt in Double Ratchet Algorithm. This section describes how to derive the receiving and sending key messages.
Alice is initialized by Bob public ...
- 159
3
votes
1
answer
574
views
X3DH Protocol - How can the receiver calculate the Shared Key?
I'm reading about Signal Protocol and X3DH Protocol. In the X3DH Protocol, Alice sends a initial message to Bob encrypted with a Shared Key(SK). This SK is calculated using (this section):
...
- 159
5
votes
2
answers
3k
views
X3DH protocol - What are One-time prekeys for?
I'm reading about Signal Protocol and this protocol uses the X3DH Protocol to establish a shared secret key between the two parties but I couldn't understand why we use one-time prekeys in the flow. ...
- 159
3
votes
1
answer
647
views
What's dh-composite test on badssl.com?
The site badssl.com provides examples of bad (red icon) and good (green icon) uses of TLS for the purpose of testing TLS implementations. I'm a bit confused by the test called dh-composite. This ...
- 41
3
votes
1
answer
894
views
Do ECDH and ECDSA combined solution provide an authenticated protocol exchange solution in MCU environment?
I'm working on a project in MCU (micro controller) environment with GPRS connection to exchange data securely with the cloud. The encryption algorithm has been selected to use AES.
I did some search ...
- 33