Google and Amazon do not offer ciphers using Diffie-Hellman Ephemeral mode.

Diffie-Hellman key exchange was designed to counter the scenario where the server's private key has been leaked to outsiders.

If the attacker was in possession of the server private key, they still would not be able to figure out the secret shared key that is independently established at both ends.

With DHE, the secret shared key never travels over the network so the attacker (who is busy decrypting the communication with the private key) still doesn't have access to the shared secret key and will be left out of the subsequent symmetrical encryption for the rest of the session.

Try wiresharking with HTTPS session using a DHE cipher, even when you load the private key, you'll find that you are still unable to decrypt.

Yes, if the attacker is in a man-in-the-middle position between client and the server, it becomes a completely different ball game and many different attacks vectors are possible.

I'm more focused on a scenario where the attacker is passively sniffing the traffic and is able to decrypt due to possessing a copy of the private key (very difficult to detect this on-going). Using DHE ciphers eliminates this scenario.

The most likely scenario: Unassuming user downloads and runs a trojan horse which starts a hidden packet capturing program. This program records all encrypted Google traffic. At a later time, the records are transferred to a remote machine under the control of the attacker. The attacker possessing the server key could decrypt and read everything. Now if DHE was in use, the attacker would not be able to divine the shared secret key necessary to view the rest of the session beyond the handshake and the encrypted traffic is still secure.

Diffie-Hellman key exchange was designed to counter the scenario where the server's private key has been leaked to outsiders.

If the attacker was in possession of the server private key, they still would not be able to figure out the secret shared key that is independently established at both ends.

With DHE, the secret shared key never travels over the network so the attacker (who is busy decrypting the communication with the private key) still doesn't have access to the shared secret key and will be left out of the subsequent symmetrical encryption for the rest of the session.

Try wiresharking with HTTPS session using a DHE cipher, even when you load the private key, you'll find that you are still unable to decrypt.

Yes, if the attacker is in a man-in-the-middle position between client and the server, it becomes a completely different ball game and many different attacks vectors are possible.

I'm more focused on a scenario where the attacker is passively sniffing the traffic and is able to decrypt due to possessing a copy of the private key (very difficult to detect this on-going). Using DHE ciphers eliminates this scenario.

The most likely scenario: Unassuming user downloads and runs a trojan horse which starts a hidden packet capturing program. This program records all encrypted Google traffic. At a later time, the records are transferred to a remote machine under the control of the attacker. The attacker possessing the server key could decrypt and read everything. Now if DHE was in use, the attacker would not be able to divine the shared secret key necessary to view the rest of the session beyond the handshake and the encrypted traffic is still secure.

Dude, I did an NMAP scan of google.com, gives me the MD5 hash for the SSL…. just listen to some packets and you got em. Those boys that did stuxnet weren’t anywhere close to Google’s headquarters, lol.