1. The Anonymous File Transfer Network
(AFTN)
Jared Rose

2. What is AFTN? A system for sending files anonymously
Uses RSA & digital signatures for establishing a user’s “identity”
Utilizes the Tor network
SSL Encryption
Onion Routing
Hidden Services
Cross platform compatible
Jared Rose

3. Goals of AFTN Users of the AFTN are anonymous
Clients can verify the “identities” of other clients and servers
File integrity/validity can be checked
MD5 hashing + file size
Synchronization of contact information between clients and servers
Jared Rose

4. Goals of AFTN (Continued)
Files are protected by end-to-end encryption
Tor + Hidden Services
Secure updating and management of encryption/signing keys on the server
Allow clients to anonymously retrieve key and address information from servers
Jared Rose

5. Why Create AFTN? Digital privacy concerns “Big Government”
Whistle blowers
Censorship
Humanitarian work
Its interesting 
Jared Rose

6. Ethical/Legal Concerns
Potential for illegal use
IP infringement
Crime
Malicious software/Spam
Encryption export laws
Open source
Jared Rose

7. How does AFTN work? Two types of hosts: Nodes connected to Tor network
Clients
Directory Servers
Nodes connected to Tor network
Outbound connections through Vidalia
Inbound connections to server sockets listening at a Tor hidden services address
Provides anonymous exchanges between hosts
End to end encryption
Jared Rose

8. Clients & Directory Servers
Clients register with a directory server
Directory servers supply contact info for clients
Clients send files to other clients (P2P)
Clients know servers contact info through white lists
Clients of non-whitelisted servers ignored
Permits organizations to be “off the grid”
Jared Rose

9. Tor Provides anonymity through onion routing Hidden Services:
NAT/Firewall traversal
End to end encryption
Hides server locations
Bandwidth/Speed are issues
Onion routing is bandwidth intensive
Speed influence by the types of node you traverse
Jared Rose

10. Anonymity and User Identity
Q. If anonymous, how do we know we are talking to the right person?
A. Public Key Cryptography!
Public/Private signing key
Jared Rose

11. Anonymity and User Identity
When clients register with a server:
Create unique name/server pair answer (name#server)
Register public “master” key used for signing other keys
Any changes to keys/information on server must be signed w/ master key
Master key can be stored separate from the rest of the system for security
Jared Rose

12. Where are we at Right Now?
Jared Rose