Collaborate Disseminate
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?
In my case: I have an old dedicated PC which I have named "server". The ISP gives it a full dynamic IP and is very hard to update dynamic DNS constantly with my records.
The (free) certificates ask for a hostname or a fixed IP. S… Continue reading What is the problem in manually implementing the SSL handshake at app layer? [closed]
I have a small ARM M0 SoC and a smartphone as actors. Encryption keys used are Elliptic curve.
My current security is implemented such that:
the SoC has 128 bit hashes of phone public keys (vs 512 bit – due to storage space constraints)
t… Continue reading Does partial public key pre-sharing and partial public key exchange improve security vs one-sided public key sharing [migrated]
Is there anything wrong with hashing(with SHA256) the shared secret generated by ECDH that is 384 bits long and using that as the AES key? Is there a difference between that and, say, truncating the 384 bits down to 256.
Edit:
And would th… Continue reading Generating AES 256 key from ECDH P-384
I know that both algorithms are similar to the Diffie-Hellman key exchange and are used for exchanging secret keys in a group but I still cannot figure out the key differences between both algorithms.
Is the difference only in the number o… Continue reading Explanation of Burmester-Desmedt group key exchange and Ingemarsson-Tang-Wong (ITW) group key exchange algorithm [migrated]
Courses giving introduction to cryptography often refer to an example where Alice and Bob need to communicate through an evil postman, and dispose each of a lock, its key and a box in which to send the message.
The solution then given is t… Continue reading Question regarding DH/RSA/Public key cryptography [closed]
In the Server hello, I got the below Cipher suite
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
Now, I know that we are using DHE for the key exchange, we are using RSA for the authentication, and AES for the encryption, and I know the complete pro… Continue reading What’s the use of HMAC or hashing in TLS or SSL inspection
When I installed the openvpn server following these instructions, the work flow was like below
Create ca.crt
Create server.key and cert
Create client.key and cert
As far as I know, when A and B are communicating with each other, A needs … Continue reading Why does the OpenVPN server need to keep client’s private key?