diff --git a/router/doc/tunnel-alt.html b/router/doc/tunnel-alt.html index fce5c910252b547c11de819d812e17e87a55a61f..66b0eb1e0ee95e5910eb8890831064b9f155a5f3 100644 --- a/router/doc/tunnel-alt.html +++ b/router/doc/tunnel-alt.html @@ -1,4 +1,4 @@ -<code>$Id: tunnel-alt.html,v 1.2 2005/01/18 11:01:55 jrandom Exp $</code> +<code>$Id: tunnel-alt.html,v 1.3 2005/01/18 11:21:12 jrandom Exp $</code> <pre> 1) <a href="#tunnel.overview">Tunnel overview</a> 2) <a href="#tunnel.operation">Tunnel operation</a> @@ -140,7 +140,7 @@ preprocessed payload must be padded to a multiple of 16 bytes.</p> <h3>2.2) <a name="tunnel.gateway">Gateway processing</a></h3> <p>After the preprocessing of messages into a padded payload, the gateway builds -a random 4 byte preIV value, iteratively encrypting it and the tunnel message as +a random 16 byte preIV value, iteratively encrypting it and the tunnel message as necessary, selects the next message ID from its outbound PRNG, and forwards the tuple {tunnelID, messageID, preIV, encrypted tunnel message} to the next hop.</p> @@ -155,13 +155,10 @@ the initial preprocessed data.</p> <p>The preIV postprocessing should be a secure transform of the received value with sufficient expansion to provide the full 16 byte IV necessary for AES256. -<i>What transform should be used - HMAC-SHA256(preIV, layerKey), using bytes -0:15 as the IV, passing on bytes 16-19 as the next step's preIV? Should +<i>What transform should be used - E(preIV, layerIVKey), where we deliver an additional postprocessing layer key to each peer during the <a href="#tunnel.request">tunnel creation</a> to reduce the potential exposure -of the layerKey? Should we replace the 4 byte preIV with a full 16 byte preIV -(even though 4 bytes will likely provide a sufficient keyspace in which to -operate, as a single tunnel pumping 100KBps would only use 60,000 IVs)?</i></p> +of the layerKey?</i></p> <h3>2.3) <a name="tunnel.participant">Participant processing</a></h3>