Category Archives: key-exchange

Explanation of Burmester-Desmedt group key exchange and Ingemarsson-Tang-Wong (ITW) group key exchange algorithm [migrated]

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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]→

Enabling ECDH KeyExchangeAlgorithm in Windows Schannel while disabling CBC based ciphersuites

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On our Windows Servers, we have disabled the following key exchange algorithms in registry
SCHANNEL\KeyExchangeAlgorithms\ECDH
SCHANNEL\KeyExchangeAlgorithms\PKCS

This leaves us with only 2 available Cipher Suites that could be offered i… Continue reading Enabling ECDH KeyExchangeAlgorithm in Windows Schannel while disabling CBC based ciphersuites→

Can a man in the middle tell what kind of encryption you’re using from a key exchange? [migrated]

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Encryption schemes typically are built on the idea that even if a man in the middle attacker knows exactly what kind of encryption you’re using, they cannot decrypt your messages without the key.
As far as I’m aware, the only mechanism whi… Continue reading Can a man in the middle tell what kind of encryption you’re using from a key exchange? [migrated]→

What is the right way to transfer public-private keypairs over intranet?

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First asked on StackOverflow and referred to this board, here:
I have an embedded system (Netburner 5441x) that encodes public-private RSA keypairs into devices. I have ported OpenSSL into the system but the embedded processor cannot make … Continue reading What is the right way to transfer public-private keypairs over intranet?→

Key distribution protocol involves only 2 parties, given E[k1,E(k2,m)]=E[k2, E(k1, m)]

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Given an one-key cipher such that:
E[k1,E(k2,m)]=E[k2, E(k1, m)]
Is there any key distribution protocol that involves only two parties (Alice and Bob) without the key distribution center?
The protocol should allow Alice to send a session k… Continue reading Key distribution protocol involves only 2 parties, given E[k1,E(k2,m)]=E[k2, E(k1, m)]→

IIS Crypto 3.2 not getting rid of Diffie-Hellman algorithms of less than 2048-bits

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I’m trying to stop a server using Diffie Hellman key exchanges of less than 2048 bits, but I’m getting confusing results.
I’ve run
Get-TlsCipherSuite | Format-Table Name, Exchange, Cipher, Hash, Certificate
and I can see
TLS_DHE_RSA_WITH_A… Continue reading IIS Crypto 3.2 not getting rid of Diffie-Hellman algorithms of less than 2048-bits→