Delete the security design document -- it has moved to the wiki, and simplify the readme

2 files changed, 6 insertions, 45 deletions

diff --git a/README.md b/README.md
index 8a3f5522..d1c39790 100644
--- a/README.md
+++ b/README.md
@@ -2,27 +2,13 @@
 
 [![Build Status](https://travis-ci.org/micahflee/onionshare.png)](https://travis-ci.org/micahflee/onionshare)
 
-OnionShare lets you securely and anonymously share files of any size. It works by starting a web server, making it accessible as a Tor onion service, and generating an unguessable URL to access and download the files. It doesn't require setting up a server on the internet somewhere or using a third party filesharing service. You host the file on your own computer and use a Tor onion service to make it temporarily accessible over the internet. The other user just needs to use Tor Browser to download the file from you.
+OnionShare lets you securely and anonymously share files of any size. It works by starting a web server, making it accessible as a Tor onion service, and generating an unguessable URL to access and download the files. It doesn't require setting up a server on the internet somewhere or using a third party file-sharing service. You host the file on your own computer and use a Tor onion service to make it temporarily accessible over the internet. The other user just needs to use Tor Browser to download the file from you.
 
-Features include:
+**Check out [the wiki](https://github.com/micahflee/onionshare/wiki) for information about how OnionShare works, what its security properties are, and how to use it.**
 
-* A user-friendly drag-and-drop graphical user interface that works in Windows, Mac OS X, and Linux
-* Ability to share multiple files and folders at once
-* Support for multiple people downloading files at once
-* Automatically copies the unguessable URL to your clipboard
-* Shows you the progress of file transfers
-* When file is done transferring, automatically closes OnionShare to reduce the attack surface
-* Localized into several languages, and supports international unicode filenames
-
-If you're interested in exactly what OnionShare does and does not protect against, read the [Security Design Document](/SECURITY.md).
-
-![Client Screenshot](/screenshots/client.png)
-![Server Screenshot](/screenshots/server.png)
-
-## Quick Start
-
-Check out [the wiki](https://github.com/micahflee/onionshare/wiki) for information about how to use OnionShare and it's various features.
-
-You can download OnionShare to install on your computer from <https://onionshare.org/>.
+**You can download OnionShare from <https://onionshare.org/>.**
 
 You can set up your development environment to build OnionShare yourself by following [these instructions](/BUILD.md).
+
+-![Client Screenshot](/screenshots/client.png)
+-![Server Screenshot](/screenshots/server.png)
diff --git a/SECURITY.md b/SECURITY.md
deleted file mode 100644
index 6389ddd5..00000000
--- a/SECURITY.md
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-# Security Design Document
-
-## How it works
-
-OnionShare is a tool that helps users securely and anonymously share files over the internet.
-
-First, the sender chooses files and folders they wish to share with the recipient. OnionShare then starts a web server at `127.0.0.1` on a random port. It chooses two words from a 6800-long wordlist called a slug, and makes the files available for download at `http://127.0.0.1:[port]/[slug]/`. It then makes the web server accessible as Tor onion service, and displays the URL `http://[onionservice].onion/[slug]` to the sender to share. A final OnionShare URL looks something like `http://f5ratndpx7rgvh7i.onion/fold-foxy`.
-
-The sender is responsible for securely sharing that URL with the recipient using a communication channel of their choice, such as in an encrypted email, chat, or voice call, or something less secure like a Twitter or Facebook message, depending on their threat model.
-
-The recipient must use Tor Browser to load the URL and download the files.
-
-As soon as the shared files get downloaded, or when the sender closes OnionShare, the Tor onion service and web servers shut down, completely removing the files from the internet (there is an option to not shut down after the first download, to allow the files to be downloaded multiple times). Because of this, OnionShare is most useful if it's used in real-time. For example, if a user runs OnionShare on their laptop, and then suspends their laptop before the files have been downloaded, the service will not be available until the laptop is unsuspended and connected to the internet again.
-
-## What it protects against
-
-* **Third parties don't have access to files being shared.** The files are hosted directly on the sender's computer and don't get uploaded to any server. Instead, the sender's computer becomes the server. Traditional ways of sending files, like in an email or using a cloud hosting service, require trusting the service with access to the files being shared.
-* **Network eavesdroppers can't spy on files in transit.** Because connections between Tor onion services and Tor Browser are end-to-end encrypted, no network attackers can eavesdrop on the shared files while the recipient is downloading them. If the eavesdropper is positioned on the sender's end, the recipient's end, or is a malicious Tor node, they will only see Tor traffic. If the eavesdropper is a malicious rendezvous node used to connect the recipient's Tor client with the sender's onion service, the traffic will be encrypted using the onion service key.
-* **Anonymity of sender and recipient are protected by Tor.** OnionShare and Tor Browser protect the anonymity of the users. As long as the sender anonymously communicates the OnionShare URL with the recipient, the recipient and eavesdroppers can't learn the identity of the sender.
-* **If an attacker enumerates the onion service, the shared files remain safe.** There have been attacks against the Tor network that can enumerate onion services. If someone discovers the .onion address of an OnionShare onion service, they still cannot download the shared files without knowing the slug. The slug is generated by choosing two random words from a list of 6800 words, meaning there are 6800^2, or about 46 million possible slugs. But they can only make 20 wrong guesses before OnionShare stops the server, preventing brute force attacks against the slug. The OnionShare server also checks request URIs using a constant time string comparison function, so timing attacks can't be used to help guess the slug.
-
-## What it doesn't protect against
-
-* **Communicating the OnionShare URL might not be secure.** The sender is responsible for securely communicating the OnionShare URL with the recipient. If they send it insecurely (such as through an email message, and their email is being monitored by an attacker), the eavesdropper will learn that they're sending files with OnionShare. If the attacker loads the URL in Tor Browser before the legitimate recipient gets to it, they can download the files being shared. If this risk fits the sender's threat model, they must find a more secure way to communicate the URL, such as in an encrypted email, chat, or voice call. This isn't necessary in cases where the files being shared aren't secret.
-* **Communicating the OnionShare URL might not be anonymous.** While OnionShare and Tor Browser allow for anonymously sending files, if the sender wishes to remain anonymous they must take extra steps to ensure this while communicating the OnionShare URL. For example, they might need to use Tor to create a new anonymous email or chat account, and only access it over Tor, to use for sharing the URL. This isn't necessary in cases where there's no need to protect anonymity, such as coworkers who know each other sharing work documents.