Service:

  1. web publishing
  2. instant messaging server
Step 1:
  1. Service advertise its existence in Tor network before clients be able to cotact it.
  2. service random找几个relays， build circuit和他们，但不是direct connection; 这几个relays就是introduction points（）, service会诉这几个relays自己的PK(Public Key), 但是我们并不想让introduction points知道ip addr, 尽管他们知道PK step1
Step 2:
  1. onion service descriptor: 我们的service装起来一个（assembles）onion service descriptor， 其中包括了: 1.PK;
    1. summary of each interduction points;
    2. 并且用private key sign this 含有PK的discriptor
  2. 之后把这个discriptor传给distributed hash table(DB), The descriptor will be found by clients requesting XYZ.onion where XYZ is a 16 character name derived from the service’s public key. client request一个地址就能找到这个discriptor. （这个名字和PK有一定关系，但是是什么关系还不太清楚）

但是这里面没有任何bob的 地址。

XYZ is an autogenerated name derived from Bob’s public key

step2

Step 3:

client  需要知道onion service的addr, 之后download descriptor, 就知道了introduction points and right public keys to use. client 也会random pick node as（rendezvous point） point by telling them a one-time secret.

step3

  • [] The downloaded advertisement record tells Alice where to find Introduction Points.
  • [] She further chooses a random Tor node to act as a Rendezvous Point, and connects to it.
Step 4:

这时候我们有了rendevous point 和 descriptor client造出来一个introduce message(encrypted to the onion service’s public key) including addr of rendezvous point + the one-time secret. 之后把这个message 给其中一个introduction points.

Step 4

Step5:

等到消息传给onion service 之后， onion service用自己的private key decrpted。 之后就知道了rendezvous point and one-time secret.

之后onion service创建rendezvous msg然后把它给rendezvous point。

记住最开始的几个introduction point很关键。

Step 5

Step6:

rendezvous point告诉client 成功连接。 Step 6

但是Tor还不够完全anonymous:

  1. Session Cookies, including third party trackers 到处都是
  2. Browser Reveal you third party:
    • 访问nytimes.com, 广告业务模块 window.location.href, 令browser发送get request to 广告网站, 这样广告网站就能用request header得到他想要的信息。

Tor Browser: All traffic through Tor. Non-tracking search engine.

Browser Fingerprint:

  1. collect enough information from a client, you can (probably) identify them uniquely • User-Agent string • Screen size • Browser plugin details • Language • Platform • Etc.
  2. Tor Browser 没有