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2020-02-17

“Why do we use ip addresses instead of mac addresses?”

because IP addresses can be nicely clustered by route

“why do we need mac addresses?”

As it turns out, according to the guy on ipspace.net, we don’t really need mac addresses anymore

We have, up to this point, looked at layer 2 and layer 3 security

next week = midterm

H.B. seems to love to talk about Bittorrent

protocol: a set of rules by which some number of parties accomplish some shared objective

“then what is an algorithm”

An algorithm can be followed by one entity

An overlay network is a layer 4 abstract network. Layers 3 and down have been abstracted away. A peer communicates with a peer, we ignore the routers and switches that facilitate this.

When sending a message over a network, how do you ensure confidentiality?

Encryption

HB’s encryption notation

sender -> receiver: { message } sub(key)

The security property of Freshness: add a sequence number

A hash is secure if collisions are sufficiently rare