For questions relating to protocols for distributing public keys, and / or establishing session keys with another party. Examples of key exchange protocols include Diffie-Hellman and IKE.

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1answer
80 views

OpenSSL's EVP functions, more specifically EVP_SealInit

Reference: https://wiki.openssl.org/index.php/Manual:EVP_SealInit%283%29 I want to securely share a symmetrical key between two endpoints using OpenSSL's EVP interface. Transferring the encrypted ...
2
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1answer
48 views

Can a user verify the quality/safety of pregenerated SSH moduli parameters?

Many tutorials about how to mitigate the Logjam recommend regenerating Diffie-Hellman moduli. This is a resource intensive operation, especially for high-bit groups. This made me think if it made ...
0
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1answer
34 views

Do I have the private keys to CAs installed on my browser?

Could someone please help explain the following comment from Why was the private key of the Superfish certificate so easily extractable? The main issue with private key extraction is the use of ...
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1answer
23 views

Replace certificates simultaneously on remote servers?

A third party server sends us signed messages that we verify. When its certificate is about to expire, the third party generates a new key pair and sends us the new certificate. At some point, the ...
3
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0answers
161 views

Main difference between Yahalom and Needham-Schroeder key exchange protocols

I am just wondering what is the main difference between the Yahalom and Needham-Schroeder key exchange protocols? Which protocol uses less computational power?
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0answers
90 views

Diffie Hellman Key Exchange in a messaging application

I'm currently a student that is trying to develop a messaging application on android using java that will implement diffie hellman key exchange in order to ensure that they both will be able to ...
2
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0answers
51 views

How rf remotes for “cloning” rolling code find matching codes?

I've been tinkering with a rf (garage door) remote control that has a scanner mode (google JMA SR-48 for details). This mode works for Mutancode and Erreka which I assume would be similar to KeeLoq. ...
2
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0answers
50 views

Can SRP be implemented using libsodium

I am using libsodium for cryptography and I want to use SRP for key exchange. The wikipedia page lists a python example, but I am not sure if and how I could convert this to libsodium function calls. ...
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0answers
33 views

AES256 key exchange

I'm trying to get a secure way of exchanging keys between my client application and the server. The goal is to encrypt all XML messages with AES256. These XML's will be transferred to the server ...
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0answers
28 views

key hierarchy management and master key

Now, I have this equation, {{K_ab}K_bs}K_as. K_ab is encrypted by K_bs then whole packet is encrypted by K_as I think the key structure is K_as is the master key, K_bs is under K_as and K_ab is the ...
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0answers
60 views

Key Hierarchy and key Encryption

If i have two 56-bit DES keys, and I use these two key to encrypt a 256-bit AES key. Like this: K_AT encrypts K_BT and K_BT encrypts K What is the effective security of key K? Is it 2 X 56 Bits?
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0answers
45 views

Migration problem between different machines using TrouSerS TPM library

My question coincides with the question posted by Maximiliano Ezequiel. Below is a question. I could make migration process work in one single machine. I can: Export SRK public key. ...
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0answers
64 views

how IKE (Internet Key Exchange) protocol reacts to the replay attack?

I mean how IKE in any mode (quick,aggressive, main) responds to an attacker that tries to replay one or more messages?
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0answers
122 views

Verifying the owner of a signing key

I'm using elliptic curve cryptography (curve25519 and ed25519) for key exchange and signing. The signing and key exchange keypairs are independent. I need two users to be able to verify each other's ...
1
vote
0answers
292 views

SSH using pre-existing session (symmetric) keys

Is there at present a way to open a SSH connection using pre-existing symmetric session keys? In other words, if I create a list of symmetric keys can I send that list to the recipient on a CD or USB ...
1
vote
0answers
256 views

Does Diffie-Hellmann (DH) key exchange protocol lower Off-The-Record protocol (OTR) security level?

Off-the-Record protocol employes Diffie-Hellman key exchange protocol (DH). DH protocol does not provide authentication of the communicating parties and, according to many sources, is vulnerable to ...
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0answers
61 views

Any Suggestion Exchanging shared key between process via port in untrusted machine (infected my malware)?

I am trying to get shared key between Firefox extension and a java program running in same machine. I am communicating both application via socket. My assumption is that malware is running in ...
0
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0answers
20 views

Key Distribution Center Key Protocol Analysis

http://i68.tinypic.com/fwu92v.png As shown in the image, why is Circle 1 to be B and Circle 2 to be A? Why is not the opposite, that is, Circle 1 to be A and Circle 2 to be B? like this picture ...
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0answers
116 views

Secure Handshake and register for Auth

The registration The Start - pre-authentication Let's assume there are Alice and Bob. They know each others public keys and each of them generates a random string - Bob's Bobkey and Alice's Alicekey....
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0answers
38 views

Preventing a key from being found by analysis

Lets say Alice wants to send an encrypted message to Bob. They both know a secret key. Alice uses the key to encrypt the message and Bob uses the key to decrypt the message. Now, if the handshake ...
0
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0answers
38 views

Distribution of key by server

I have read that in asymmetric cryptography, a system admin can generate key pairs on the server. After that, the users will be given the generated key pairs and this is an efficient way of doing this ...