Method & Apparatus for Providing Secure Streaming Data Transmission Facilities Using Unreliable Protocols

• US 20080104390A1
• Filed: 10/29/2007
• Published: 05/01/2008
• Est. Priority Date: 02/12/2001
• Status: Active Grant

• Current Assignee: Aventail LLC
• Original Assignee: Aventail LLC
• Inventors: VanHeyningen, Marc, Erickson, Rodger
• Granted Patent: US 7,870,380 B2
• Time in Patent Office: Days
• US Class Current: 713/151
• CPC Class Codes: H04L 2209/76 Proxy, i.e. using intermediary entity to perform cryptographic operations network architectures or network communication protocols using hop-by-hop encryption H04L63/0464
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0457 wherein the sending and receiving network entities apply dynamic encryption, e.g. stream encryption cryptographic mechanisms or cryptographic arrangements for stream encryption H04L9/065
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 63/166 at the transport layer
• CPC Class Codes: H04L 9/0838 Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these network architectures or network communication protocols for key exchange in a packet data network H04L63/061
• CPC Class Codes: H04L 9/12 Transmitting and receiving encryption devices synchronised or initially set up in a particular manner
• CPC Class Codes: H04L 9/32 including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials

Abstract

The invention provides a method and apparatus for transmitting data securely using an unreliable communication protocol, such as User Datagram Protocol. In one variation, the invention retains compatibility with conventional Secure Sockets Layer (SSL) and SOCKS protocols, such that secure UDP datagrams can be transmitted between a proxy server and a client computer in a manner analogous to conventional SOCKS processing. In contrast to conventional SSL processing, which relies on a guaranteed delivery service such as TCP and encrypts successive data records with reference to a previously-transmitted data record, encryption is performed using a nonce that is embedded in each transmitted data record. This nonce acts both as an initialization vector for encryption/decryption of the record, and as a unique identifier to authenticate the record. Because decryption of any particular record does not rely on receipt of a previously received data record, the scheme will operate over an unreliable communication protocol. The system and method allows secure packet transmission to be provided with a minimum amount of overhead. Further, the invention provides a network arrangement that employs a cache having copies distributed among a plurality of different locations. SSL/TLS session information for a session with each of the proxy servers is stored in the cache so that it is accessible to at least one other proxy server. Using this arrangement, when a client computer switches from a connection with a first proxy server to a connection with a second proxy server, the second proxy server can retrieve SSL/TLS session information from the cache corresponding to the SSL/TLS communication session between the client device and the first proxy server. The second proxy server can then use the retrieved SSL/TLS session information to accept a session with the client device.

Claims

1. A method of transmitting data securely over a computer network, comprising the steps of:

(1) establishing a communication path between a first computer and a second computer;

(2) encrypting and transmitting data records between the first computer and the second computer using an unreliable communication protocol, wherein each data record is encrypted without reference to a previously transmitted data record;

in the second computer, receiving and decrypting the data records transmitted in step (2) without reference to a previously received data record; and

(4) in the second computer, transmitting session information for encrypting and decrypting the data records to a third computer.

2-46. -46. (canceled)