Fishy Fishy Fishy

Transport Layer
---------------

available anonymity
node addressability
session support
automatic/dynamic/cyclical (re)configuration
encryption
per-node incryption

!!node compromisation


routing:

  Nodes form an interconnected broadcast network with link coloring. Each node
  has a list of links to other nodes (this is a non-exhaustive list of random
  nodes from the pool of all nodes). A packet traverses the network by passing
  into a node from another node. If the node in question has a connection out to
  the node it got the packet from, it marks that connection as already having seen
  the message. The node then sends the message over the rest of its connections,
  marking them each in turn. Every packet contains a token that the source node
  recognizes, so that the source node can be addressed without betraying its 
  identification. This token changes for every session (sessions could be tracked).

  anonymiser:
    a connection though the network can be established from a client to a tcp target
    outside the network by sending a special packet that has a Time To Live. The TTL
    is decrimented as the packet traveses each node. When the TTL reaches 0, the node
    it is in becomes an end node and sends a message over the network addressed to the
    source of the packet with its session ID offering to establish a connection. The
    client can then communicate with the end node in an on going basis using its session
    ID, thus establishing an anonymous connection.

    streams would use key exchange to eliminate casual snooping, keys would be provided
    with the initial packets in the establishment of the connection.



Proposed packet format:

32 bit network order unsigned ints
    0       1       2       3       4       5       6       7  
+-------+-------+-------+-------+-------+-------+-------+-------+
|opt bmp| source token  |  dest. token  |pkt id |  TTL  |command|
+-------+-------+-------+-------+-------+-------+-------+-------+
|datalen|Data ... 
+-------+--------


 opt bmp:
   Options for leaving out various parts of the packet
      bit      purpose (on = this)
      --------------------------
       0       no source token present
       1       no destination token present
       2       no TTL present
       3       no data present (also no datalen present)
       4..31   future use

  source token:
    A unique identifier for this session for the originating node
  
  destination token:
    A unique identifier for this session for the target node

  packet id:
    A unique identifier, paired with other information in this packet
    used for route coloring

  TTL:
    Time To Live, for packets without a destination, when TTL is 0,
    the command will be executed, otherwise the packet will be dropped.

  command:
    The command to execute by the distination node or the the TTL 0 node.

  data length:
    The length in bytes of the data associated with this packet. THe semantic
    purpose of the data is determined by the command field.


synchronization:

  Covert nodes would synchronize using a general method of searching for centain
  kinds of websites (those with a guestbook are most likely) and then posting to
  them. The content would be generated by a markov chainer based on other content
  from the page or based on content from the owner's cache. The content would follow
  the general pattern of a positive comment about a website, but contain the chained
  sequences, deliniated with special algorithmicly derived guardwords which would
  encode the node's identificiation. Nodes wishing to synchronize with other nodes
  would do searches for the specific kind of site, and then read the site, locating
  the deliniated passages and deriving node identifiers from them, thus allowing the
  nodes that posted the messages to be located.