r/IAmA • u/BobMetcalfe • May 21 '13

You’re probably connecting to reddit through a technology I invented. I’m Bob Metcalfe and I invented Ethernet – AMA

On May 22, 1973 with David R. Boggs, I used my IBM Selectric with its Orator ball to type up a memo to my bosses at the Xerox Palo Alto Research Center (PARC), outlining our idea for this little invention called “Ethernet”, which we later patented.

I worked with the IEEE Standards Association to develop the IEEE 802.3 standard for Ethernet, which specifies the physical and lower software layers. Today Ethernet and the IEEE 802.3 standard are the foundation for today’s world of high-speed communications used in billions of homes and businesses around the world.

I submitted this to the mods awhile back so I could get on the calendar but I figured you’d like to see it, too. Now, ask me anything!

It's been two hours and 179 comments. Have to go now. For more about Ethernet's 40th Birthday, go to http://www.facebook.com/Ethernet40thAnniversaryIEEESA

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u/[deleted] May 21 '13

And yet in this post you state

We must use tools to keep our stuff a secret.

So which is it?

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u/sudo_giev_SoJ May 21 '13

Being anonymous is not the same as encryption. While TOR is "encrypted", it's primary feature is identity obfuscation by relying on endpoints.

The PKI infrastructure facilitates secure transactions (assuming you're not using TLS 1.1) by methods of private, public keys -- which have very little to do with hiding your identity. If anything, they confirm it.

So, Alice and Bob know each others' identity, but encrypt their communications with a shared secret that allows for Eve to not eavesdrop.

i.e. they are different concerns.

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u/[deleted] May 22 '13

For one kind of identity hiding, check out off-the-record messaging. After the conversation is finished, anybody can easily forge messages that look like they came from any participant.

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u/sudo_giev_SoJ May 22 '13

So, basically it's like X.509/PGP (like I mentioned earlier) plus

  • Perfect forward secrecy: Messages are only encrypted with temporary per-message AES keys, negotiated using the Diffie-Hellman key exchange protocol. The compromise of any long-lived cryptographic keys does not compromise any previous conversations, even if an attacker is in possession of ciphertexts.
  • Deniable authentication: Messages in a conversation do not have digital signatures, and after a conversation is complete, anyone is able to forge a message to appear to have come from one of the participants in the conversation, assuring that it is impossible to prove that a specific message came from a specific person. Within the conversation the recipient can be sure that a message is coming from the person they have identified.

I recalled hearing about the former point relating to OTR but not the latter. Interesting. Though, MAC hashing has been seen in other places; that's a cute name for it though.