WO2001045351A2

WO2001045351A2 - Scalable security for groups in a virtual private network

Info

Publication number: WO2001045351A2
Application number: PCT/US2000/042640
Authority: WO
Inventors: Germano Caronni; Amit Gupta; Tom R. Markson; Sandeep Kumar; Christoph L. Schuba; Glenn C. Scott
Original assignee: Sun Microsystems, Inc.
Priority date: 1999-12-10
Filing date: 2000-12-08
Publication date: 2001-06-21
Also published as: WO2001045351A3; AU4712501A

Abstract

Methods and systems consistent with the present invention provide a Supernet, a private network constructed out of components from a public-network infrastructure. Supernet modes can be located on virtually any device in the public network (e.g. the Internet), and both their communication and utilization of resources occur in a secure manner through the use of key management. Key management provides for the use of a key, representing a type of encryption, which is solely associated with a particular channel within the network and changes frequently to heigthen security. As a result, the users of a Supernet benefit from their network infrastructure being maintained for them as part of the public network infrastructure, while the level of security they receive is similar to that of a private network. Additionally, the nodes of the Supernet are not geographically restricted in that they can be connected to the Supernet from virtually any portal to the Internet in the world.

Description

SCALABLE SECURITY ASSOCIATIONS FOR GROUPS FOR USE IN A

PRIVATE NETWORK USING A PUBLIC-NETWORK INFRASTRUCTURE

FIELD OF THE INVENTION The present invention relates generally to data processing systems and, more

particularly, to a private network using a public-network infrastructure.

BACKGROUND OF THE INVENTION

As part of their day-to-day business, many organizations require an enterprise

network, a private network with lease lines, dedicated channels, and network connectivity

devices, such as routers, switches, and bridges. These components, collectively known as

the network's "infrastructure," are very expensive and require a staff of information

technology personnel to maintain them. This maintenance requirement is burdensome on

many organizations whose main business is not related to the data processing industry

(e.g., a clothing manufacturer) because they are not well suited to handle such data

processing needs.

Another drawback to enterprise networks is that they are geographically

restrictive. The term "geographically restrictive" refers to the requirement that if a user is

not physically located such that they can plug their device directly into the enterprise

network, the user cannot typically utilize it. To alleviate the problem of geographic

restrictiveness, virtual private networks have been developed.

In a virtual private network (VPN), a remote device or network connected to the

Internet may connect to the enterprise network through a firewall. This allows the remote

device to access resources on the enterprise network even though it may not be located near any component of the enterprise network. For example, Fig. 1 depicts a VPN 100,

where enterprise network 102 is connected to the Internet 104 via firewall 106. By using

VPN 100, a remote device D, 108 may communicate with enterprise network 102 via

Internet 104 and firewall 106. Thus, D, 108 may be plugged into an Internet portal

virtually anywhere within the world and make use of the resources on enterprise network

102.

To perform this functionality, D, 108 utilizes a technique known as tunneling to

ensure that the communication between itself and enterprise network 102 is secure in that

it cannot be viewed by an interloper. "Tunneling" refers to encapsulating one packet

inside another when packets are transferred between end points (e.g., D, 108 and VPN

software 109 running on firewall 106). The packets may be encrypted at their origin and

decrypted at their destination. For example, Fig. 2A depicts a packet 200 with a source

Internet protocol (IP) address 202, a destination IP address 204, and data 206. It should

be appreciated that packet 200 contains other information not depicted, such as the source

and destination port. As shown in Fig. 2B, the tunneling technique forms a new packet

208 out of packet 200 by encrypting it and adding both a new source IP address 210 and a

new destination IP address 212. In this manner, the contents of the original packet (i.e.,

202, 204, and 206) are not visible to any entity other than the destination. Referring back

to Fig. 1, by using tunneling, remote device D, 108 may communicate and utilize the

resources of the enterprise network 102 in a secure manner.

Although VPNs alleviate the problem of geographic restrictiveness, they impose

significant processing overhead when two remote devices communicate. For example, if

remote device D, 108 wants to communicate with remote device D₂ 1 10, D, sends a packet using tunneling to VPN software 109, where the packet is decrypted and then

transferred to the enterprise network 102. Then, the enterprise network 102 sends the

packet to VPN software 109, where it is encrypted again and transferred to D₂ Given this

processing overhead, it is burdensome for two remote devices to communicate in a VPN

environment. It is therefore desirable to alleviate the need of organizations to maintain

their own network infrastructure as well as to improve communication between remote

devices.

SUMMARY OF THE INVENTION

Accordingly, systems and methods consistent with the present invention

substantially obviate one or more of the problems due to limitations, shortcomings, and

disadvantages of the related art by providing for a network that allows secure

communications between nodes allowed access to the network through the use of key

management.

In accordance with the present invention, as embodied and broadly described

herein, a system and method for communication within a network is provided having a

set of nodes where a channel of communication is established within the network; a key

is specified for the channel; access to the key is provided to each node in the set; and

communication is permitted on the channel by the set of nodes with access to the key.

Both the foregoing general description and the following detailed description are

exemplary and explanatory only, and merely provide further explanation of the claimed

invention. BRIEF DESCRIPTION OF THE DRAWINGS

This invention is pointed out with particularity in the appended claims. The

above and further advantages of this invention may be better understood by referring to

the following description taken in conjunction with the accompanying drawings, in

which:

Fig. 1 depicts a conventional virtual private network (VPN) system;

Fig. 2A depicts a conventional network packet;

Fig. 2B depicts the packet of Fig. 2A after it has been encrypted in accordance

with a conventional tunneling technique;

Fig. 3 depicts a data processing system suitable for use with methods and systems

consistent with the present invention;

Fig. 4 depicts the nodes depicted in Fig. 3 communicating over multiple channels;

Fig. 5 depicts two devices depicted in Fig. 3 in greater detail;

Figs. 6A and 6B depict a flow chart of the steps performed when a node joins a

VPN in a manner consistent with the present invention;

Fig. 7 depicts a flow chart of the steps performed when sending a packet from a

node of the VPN in a manner consistent with the present invention;

Fig. 8 depicts a flow chart of the steps performed when receiving a packet by a

node of the VPN in a manner consistent with the present invention; and

Fig. 9 depicts a flow chart of the steps performed when logging out of a VPN in a

manner consistent with the present invention. DETAILED DESCRIPTION

Methods and systems consistent with the present invention provide a "Supemet,"

which is a private network that uses components from a public-network infrastructure. A

Supemet allows an organization to utilize a public-network infrastructure for its

enterprise network so that the organization no longer has to maintain a private network

infrastructure; instead, the organization may have the infrastructure maintained for them

by one or more service providers or other organizations that specialize in such

connectivity matters. As such, the burden of maintaining an enterprise network is greatly

reduced. Moreover, a Supemet is not geographically restrictive, so a user may plug their

device into the Internet from virtually any portal in the world and still be able to use the

resources of their private network in a secure and robust manner.

Overview

Fig. 3 depicts a data processing system 300 suitable for use with methods and

systems consistent with the present invention. Data processing system 300 comprises a

number of devices, such as computers 302-312, connected to a public network, such as

the Internet 314. A Supernet's infrastructure uses components from the Internet because

devices 302, 304, and 312 contain nodes that together form a Supemet and that

communicate by using the infrastructure of the Internet. These nodes 316, 318, 320, and

322 are communicative entities (e.g., processes) running within a particular device and

are able to communicate among themselves as well as access the resources of the

Supemet in a secure manner. When communicating among themselves, the nodes 316,

318, 320, and 322 serve as end points for the communications, and no other processes or devices that are not part of the Supemet are able to communicate with the Supernet's

nodes or utilize the Supernet's resources. The Supemet also includes an administrative

node 306 to administer to the needs of the Supemet. It should be noted that since the

nodes of the Supemet rely on the Internet for connectivity, if the device on which a node

is running relocates to another geographic location, the device can be plugged into an

Internet portal and the node running on that device can quickly resume the use of the

resources of the Supemet. It should also be noted that since a Supemet is layered on top

of an existing network, it operates independently of the transport layer. Thus, the nodes

of a Supemet may communicate over different transports, such as IP, IPX, X.25, or

ATM, as well as different physical layers, such as RF communication, cellular

communication, satellite links, or land-based links.

As shown in Fig. 4, a Supemet includes a number of channels that its nodes 316-

322 can communicate over. A "channel" refers to a collection of virtual links through the

public-network infrastructure that connect the nodes on the channel such that only these

nodes can communicate over it. A node on a channel may send a message to another

node on that channel, known as a unicast message, or it can send a message to all other

nodes on that channel, known as a multicast message. For example, channel 1 402

connects node A 316 and node C 320, and channel 2 404 connects node B 318, node C

320, and node D 322. Each Supemet has any number of preconfigured channels over

which the nodes on that channel can communicate. In an alternative embodiment, the

channels are dynamically defined.

In addition to communication, the channels may be used to share resources. For

example, channel 1 402 may be configured to share a file system as part of node C 320 such that node A 316 can utilize the file system of node C in a secure manner. In this

case, node C 320 serves as a file system manager by receiving file system requests (e.g.,

open, close, read, write, etc.) and by satisfying the requests by manipulating a portion of

the secondary storage on its local machine. To maintain security, node C 320 stores the

data in an encrypted form so that it is unreadable by others. Such security is important

because the secondary storage may not be under the control of the owners of the

Supemet, but may instead be leased from a service provider. Additionally, channel 2404

may be configured to share the computing resources of node D 322 such that nodes B 318

and C 320 send code to node D for execution. By using channels in this manner,

resources on a public network can be shared in a secure manner.

A Supemet provides a number of features to ensure secure and robust

communication among its nodes. First, the system provides authentication and admission

control so that nodes become members of the Supemet under strict control to prevent

unauthorized access. Second, the Supemet provides communication security services so

that the sender of a message is authenticated and communication between end points

occurs in a secure manner by using encryption. Third, the system provides key

management to reduce the possibility of an intruder obtaining an encryption key and

penetrating a secure communication session. The system does so by providing one key

per channel and by changing the key for a channel whenever a node joins or leaves the

channel. Alternatively, the system may use a different security policy.

Fourth, the system provides address translation in a transparent manner. Since the

Supemet is a private network constructed from the infrastructure of another network, the

Supemet has its own internal addressing scheme, separate from the addressing scheme of the underlying public network. Thus, when a packet from a Supemet node is sent to

another Supemet node, it travels through the public network. To do so, the Supemet

performs address translation from the internal addressing scheme to the public addressing

scheme and vice versa. To reduce the complexity of Supemet nodes, system-level

components of the Supemet perform this translation on behalf of the individual nodes so

that it is transparent to the nodes. Another benefit of the Supernet's addressing is that it

uses an IP-based internal addressing scheme so that preexisting programs require little

modification to run within a Supemet.

Lastly, the Supemet provides operating system-level enforcement of node

compartmentalization in that an operating system-level component treats a Supemet node

running on a device differently than it treats other processes on that device. This

component (i.e., a security layer in a protocol stack) recognizes that a Supemet node is

part of a Supemet, and therefore, it enforces that all communications to and from this

node travel through the security infrastructure of the Supemet such that this node can

communicate with other members of the Supemet and that non-members of the Supemet

cannot access this node. Additionally, this operating system-level enforcement of node

compartmentalization allows more than one Supemet node to run on the same machine,

regardless of whether the nodes are from the same Supemet, and allows nodes of other

networks to run on the same machine as a Supemet node.

Implementation Details

Fig. 5 depicts administrative machine 306 and device 302 in greater detail,

although the other devices 304 and 308-312 may contain similar components. Device

302 and administrative machine 306 communicate via Internet 314. Each device contains

similar components, including a memory 502, 504; secondary storage 506, 508; a central

processing unit (CPU) 510, 512; an input device 514, 516; and a video display 518, 520.

One skilled in the art will appreciate that these devices may contain additional or

different components.

Memory 504 of administrative machine 306 includes the SASD process 540,

VARPD 548, and KMS 550 all mnning in user mode. That is, CPU 512 is capable of

running in at least two modes: user mode and kernel mode. When CPU 512 executes

programs mnning in user mode, it prevents them from directly manipulating the hardware

components, such as video display 518. On the other hand, when CPU 512 executes

programs mnning in kernel mode, it allows them to manipulate the hardware

components. Memory 504 also contains a VARPDB 551 and a TCP/IP protocol stack

552 that are executed by CPU 512 mnning in kernel mode. TCP/IP protocol stack 552

contains a TCP/UDP layer 554 and an IP layer 556, both of which are standard layers

well known to those of ordinary skill in the art. Secondary storage 508 contains a

configuration file 558 that stores various configuration-related information (described

below) for use by SASD 540.

SASD 540 represents a Supemet: there is one instance of an SASD per Supemet,

and it both authenticates nodes and authorizes nodes to join the Supemet. VARPD 548

has an associated component, VARPDB 551, into which it stores mappings of the internal Supemet addresses, known as a node IDs, to the network addresses recognized

by the public-network infrastructure, known as the real addresses. The "node ID" may

include the following: a Supemet ID (e.g., 0x123), reflecting a unique identifier of the

Supemet, and a virtual address, comprising an IP address (e.g., 10.0.0.1). The "real

address" is an IP address (e.g., 10.0.0.2) that is globally unique and meaningful to the

public-network infrastructure. In a Supemet, one VARPD runs on each machine, and it

may play two roles. First, a VARPD may act as a server by storing all address mappings

for a particular Supemet into its associated VARPDB. Second, regardless of its role as a

server or not, each VARPD assists in address translation for the nodes on its machine. In

this role, the VARPD stores into its associated VARPDB the address mappings for its

nodes, and if it needs a mapping that it does not have, it will contact the VARPD that acts

as the server for the given Supemet to obtain it.

KMS 550 performs key management by generating a new key every time a node

joins a channel and by generating a new key every time a node leaves a channel. There is

one KMS per channel in a Supemet.

To configure a Supemet, a system administrator creates a configuration file 558

that is used by SASD 540 when starting or reconfiguring a Supemet. This file may

specify: (1) the Supemet name, (2) all of the channels in the Supemet, (3) the nodes that

communicate over each channel, (4) the address of the KMS for each channel, (5) the

address of the VARPD that acts as the server for the Supemet, (6) the user IDs of the

users who are authorized to create Supemet nodes, (7) the authentication mechanism to

use for each user of each channel, and (8) the encryption algorithm to use for each

channel. Although the configuration information is described as being stored in a configuration file, one skilled in the art will appreciate that this information may be

retrieved from other sources, such as databases or interactive configurations.

After the configuration file is created, it is used to start a Supemet. For example,

when starting a Supemet, the system administrator first starts SASD, which reads the

configuration information stored in the configuration file. Then, the administrator starts

the VARPD on the administrator's machine, indicating that it will act as the server for the

Supemet and also starts the KMS process. After this processing has completed, the

Supemet is ready for nodes to join it.

Memory 502 of device 302 contains SNlogin script 522, SNlogout script 524,

VARPD 526, KMC 528, KMD 530, and node A 522, all mnning in user mode. Memory

502 also includes TCP/IP protocol stack 534 and VARPDB 536 running in kernel mode.

SNlogin 522 is a script used for logging into a Supemet. Successfully executing

this script results in a Unix shell from which programs (e.g., node A 522) can be started

to n within the Supemet context, such that address translation and security

encapsulation is performed transparently for them and all they can typically access is

other nodes on the Supemet. Alternatively, a parameter may be passed into SNlogin 522

that indicates a particular process to be automatically mn in a Supemet context. Once a

program is mnning in a Supemet context, all programs spawned by that program also mn

in the Supemet context, unless explicitly stated otherwise. SNlogout 524 is a script used

for logging out of a Supemet. Although both SNlogin 522 and SNlogout 524 are

described as being scripts, one skilled in the art will appreciate that their processing may

be performed by another form of software. VARPD 526 performs address translation

between node IDs and real addresses. KMC 528 is the key management component for each node that receives updates whenever the key for a channel ("the channel key")

changes. There is one KMC' per node per channel. KMD 530 receives requests from

SNSL 542 of the TCP/IP protocol stack 534 when a packet is received and accesses the

appropriate KMC for the destination node to retrieve the appropriate key to decrypt the

packet. Node A 532 is a Supemet node mnning in a Supemet context.

TCP/IP protocol stack 534 contains a standard TCP/UDP layer 538, two standard

IP layers (an inner IP layer 540 and an outer IP layer 544), and a Supemet security layer

(SNSL) 542, acting as the conduit for all Supemet communications. To conserve

memory, both inner IP layer 540 and outer IP layer 544 may share the same instance of

the code of an IP layer. SNSL 542 performs security functionality as well as address

translation. It also caches the most recently used channel keys for ten seconds. Thus,

when a channel key is needed, SNSL 542 checks its cache first, and if it is not found, it

requests KMD 530 to contact the appropriate KMC to retrieve the appropriate channel

key. Two IP layers 540, 544 are used in the TCP/IP protocol stack 534 because both the

internal addressing scheme and the external addressing scheme are IP-based. Thus, for

example, when a packet is sent, inner IP layer 540 receives the packet from TCP/UDP

layer 538 and processes the packet with its node ID address before passing it to the SNSL

layer 542, which encrypts it, prepends the real source IP address and the real destination

IP address, and then passes the encrypted packet to outer IP layer 544 for sending to the

destination.

SNSL 542 utilizes VARPDB 536 to perform address translation. VARPDB

stores all of the address mappings encountered thus far by SNSL 542. If SNSL 542

requests a mapping that VARPDB 536 does not have, VARPDB communicates with the VARPD 526 on the local machine to obtain the mapping. VARPD 526 will then contact

the VARPD that acts as the server for this particular Supemet to obtain it.

Although aspects of the present invention are described as being stored in

memory, one skilled in the art will appreciate that these aspects can also be stored on or

read from other types of computer-readable media, such as secondary storage devices,

like hard disks, floppy disks, or CD-ROM; a carrier wave from a network, such as the

Internet; or other forms of RAM or ROM either currently known or later developed.

Additionally, although a number of the software components are described as being

located on the same machine, one skilled in the art will appreciate that these components

may be distributed over a number of machines.

Figs. 6A and 6B depict a flow chart of the steps performed when a node joins a

Supemet. The first step performed is that the user invokes the SNlogin script and enters

the Supemet name, their user ID, their password, and a requested virtual address (step

602). Of course, this information depends on the particular authentication mechanism

used. Upon receiving this information, the SNlogin script performs a handshaking with

SASD to authenticate this information. In this step, the user may request a particular

virtual address to be used, or alternatively, the SASD may select one for them. Next, if

any of the information in step 602 is not validated by SASD (step 604), processing ends.

Otherwise, upon successful authentication, SASD creates an address mapping between a

node ID and the real address (step 606). In this step, SASD concatenates the Supemet ID

with the virtual address to create the node ID, obtains the real address of the SNlogin

script by querying network services in a well-known manner, and then registers this information with the VARPD that acts as the server for this Supemet. This VARPD is

identified in the configuration file.

After creating the address mapping, SASD informs the KMS that there is a new

Supemet member that has been authenticated and admitted (step 608). In this step,

SASD sends the node ID and the real address to KMS who then generates a key ID, a key

for use in communicating between the node's KMC and the KMS ("a node key"), and

updates the channel key for use in encrypting traffic on this particular channel (step 610).

Additionally, KMS sends the key ID and node key to SASD and distributes the channel

key to all KMCs on the channel as a new key because a node has just been added to the

channel. SASD receives the key ID and the node key from KMS and returns it to

SNlogin (step 612). After receiving the key ID and the node key from SASD, SNlogin

starts a KMC for this node and transmits to the KMC the node ID, the key ID, the node

key, the address of the VARPD that acts as the server for this Supemet, and the address

of KMS (step 614). The KMC then registers with the KMD indicating the node it is

associated with, and KMC registers with KMS for key updates (step 616). When

registering with KMS, KMC provides its address so that it can receive updates to the

channel key via the Versakey protocol. The Versakey protocol is described in greater

detail in IEEE Journal on Selected Areas in Communication, Vol. 17, No. 9, 1999, pp.

1614-1631. After registration, the KMC will receive key updates whenever a channel

key changes on one of the channels that the node communicates over.

Next, SNlogin configures SNSL (step 618 in Fig. 6B). In this step, SNlogin

indicates which encryption algorithm to use for this channel and which authentication

algorithm to use, both of which are received from the configuration file via SASD. SNSL stores this information in an access control list. In accordance with methods and

systems consistent with present invention, any of a number of well-known encryption

algorithms may be used, including the Data Encryption Standard (DES), Triple-DES, the

International Data Encryption Algorithm (IDEA), and the Advanced Encryption Standard

(AES). Also, RC2, RC4, and RC5 from RSA Incorporated may be used as well as

Blowfish from Counterpane.com. Additionally, in accordance with methods and systems

consistent with the present invention, any of a number of well-known authentication

algorithms may be used, including Digital Signatures, Kerberos, Secure Socket Layer

(SSL), and MD5, which is described in RFCl 321 of the Internet Engineering Task Force,

April, 1992.

After configuring SNSL, SNlogin invokes an operating system call, SETVIN, to

cause the SNlogin script to n in a Supemet context (step 620). In Unix, each process

has a data stmcture known as the "proc stmcture" that contains the process ID as well as a

pointer to a virtual memory description of this process. In accordance with methods and

systems consistent with the present invention, the channel IDs indicating the channels

over which the process communicates as well as its virtual address for this process are

added to this stmcture. By associating this information with the process, the SNSL layer

can enforce that this process mns in a Supemet context. Although methods and systems

consistent with the present invention are described as operating in a Unix environment,

one skilled in the art will appreciate that such methods and systems can operate in other

environments. After the SNlogin script mns in the Supemet context, the SNlogin script

spawns a Unix program, such as a Unix shell or a service daemon (step 622). In this step,

the SNlogin script spawns a Unix shell from which programs can be mn by the user. All of these programs will thus run in the Supemet context until the user mns the SNlogout

script.

Fig. 7 depicts a flow chart of the steps performed when sending a packet from

node A. Although the steps of the flow chart are described in a particular order, one

skilled in the art will appreciate that these steps may be performed in a different order.

Additionally, although the SNSL layer is described as performing both authentication and

encryption, this processing is policy driven such that either authentication, encryption,

both, or neither may be performed. The first step performed is for the SNSL layer to

receive a packet originating from node A via the TCP/UDP layer and the inner IP layer

(step 702). The packet contains a source node ID, a destination node ID, and data. The

SNSL layer then accesses the VARPDB to obtain the address mapping between the

source node ID and the source real address as well as the destination node ID and the

destination real address (step 704). If they are not contained in the VARPDB because

this is the first time a packet has been sent from this node or sent to this destination, the

VARPDB accesses the local VARPD to obtain the mapping. When contacted, the

VARPD on the local machine contacts the VARPD that acts as the server for the

Supemet to obtain the appropriate address mapping.

After obtaining the address mapping, the SNSL layer determines whether it has

been configured to communicate over the appropriate channel for this packet (step 706).

This configuration occurs when SNlogin mns, and if the SNSL has not been so

configured, processing ends. Otherwise, SNSL obtains the channel key to be used for

this channel (step 708). The SNSL maintains a local cache of keys and an indication of

the channel to which each key is associated. Each channel key is time stamped to expire in ten seconds, although this time is configurable by the administrator. If there is a key

located in the cache for this channel, SNSL obtains the key. Otherwise, SNSL accesses

KMD which then locates the appropriate channel key from the appropriate KMC. After

obtaining the key, the SNSL layer encrypts the packet using the appropriate encryption

algorithm and the key previously obtained (step 710). When encrypting the packet, the

source node ID, the destination node ID, and the data may be encrypted, but the source

and destination real addresses are not, so that the real addresses can be used by the public

network infrastructure to send the packet to its destination.

After encrypting the packet, the SNSL layer authenticates the sender to verify that

it is the bona fide sender and that the packet was not modified in transit (step 712). In

this step, the SNSL layer uses the MD5 authentication protocol, although one skilled in

the art will appreciate that other authentication protocols may be used. Next, the SNSL

layer passes the packet to the IP layer where it is then sent to the destination node in

accordance with known techniques associated with the IP protocol (step 714).

Fig. 8 depicts a flow chart of the steps performed by the SNSL layer when it

receives a packet. Although the steps of the flow chart are described in a particular order,

one skilled in the art will appreciate that these steps may be performed in a different

order. Additionally, although the SNSL layer is described as performing both

authentication and encryption, this processing is policy driven such that either

authentication, encryption, both, or neither may be performed. The first step performed

by the SNSL layer is to receive a packet from the network (step 801). This packet

contains a real source address and a real destination address that are not encrypted as

well as a source node ID, a destination node ID, and data that are encrypted. Then, it determines whether it has been configured to communicate on this channel to the

destination node (step 802). If SNSL has not been so configured, processing ends.

Otherwise, the SNSL layer obtains the appropriate key as previously described (step

804). It then decrypts the packet using this key and the appropriate encryption algorithm

(step 806). After decrypting the packet, the SNSL layer authenticates the sender and

validates the integrity of the packet (step 808), and then it passes the packet to the inner

IP layer for delivery to the appropriate node (step 810). Upon receiving the packet, the

inner IP layer uses the destination node ID to deliver the packet.

Fig. 9 depicts a flow chart of the steps performed when logging a node out of a

Supemet. The first step performed is for the user to n the SNlogout script and to enter a

node ID (step 902). Next, the SNlogout script requests a log out from SASD (step 904).

Upon receiving this request, SASD removes the mapping for this node from the VARPD

that acts as the server for the Supemet (step 906). SASD then informs KMS to cancel

the registration of the node, and KMS terminates this KMC (step 908). Lastly, KMS

generates a new channel key for the channels on which the node was communicating

(step 910) to provide greater security.

Although the present invention has been described with reference to a preferred

embodiment, those skilled in the art will know of various changes in form and detail

which may be made without departing from the spirit and scope of the present invention

as defined in the appended claims and their full scope of equivalents.

Claims

CLAIMSWhat is claimed is:

1. A method for communication within a network having a set of nodes

comprising the steps of:

establishing a channel for communication within the network;

specifying a key for the channel;

providing access to the key by each node in the set; and

permitting communication on the channel by the set of nodes with access to the

key.

2. The method of claim 1, wherein the permitting step includes:

controlling communication on the channel using the key.

3. The method of claim 2, wherein the permitting step includes:

maintaining information identifying the set of nodes with shared access to the

key.

4. The method of claim 2, wherein the permitting step includes:

maintaining the key associated with each node for accessing the channel.

5. The method of claim 4, wherein the maintaining step includes:

providing for a key management server which maintains the key for the channel;

and

maintaining contact between each node and the key management server.

6. The method of claim 2, wherein the controlling step includes:

providing a key management server within the network;

providing a key management control associated with each of the set of nodes; and receiving by the key management control associated with each node a notification

from the key management server including a new key for the channel.

7. The method of claim 6, wherein the receiving step occurs when a new node joins

the channel.

8. The method of claim 6, wherein the receiving step occurs when a node leaves the

channel.

9. The method of claim 6, wherein the receiving step dynamically occurs.

10. The method of claim 1, wherein the permitting step includes:

providing for authentication of a node with an administrative module to establish

access to a channel.

1 1. The method of claim 1, wherein the providing step includes:

controlling access to the channel.

12. The method of claim 1, wherein the providing step includes:

providing for an administrative module to access the key from a key management

server to provide access to the channel.

13. A system for communicating within a network having a set of nodes comprising:

an establishing module configured to establish a channel for communication

within the network;

a specifying module configured to specify a key for the channel;

a providing module configured to provide access to the key by each node in the

set; and

a permitting module configured to permit communication on the channel by the

set of nodes with access to the key.

14. The system of claim 13, wherein the permitting module includes a module for

controlling communication on the channel using the key.

15. The system of claim 14, wherein the permitting module includes a module for

maintaining information identifying the set of nodes with shared access to the key.

16. The system of claim 14, wherein the permitting module includes a module for

maintaining the key associated with each node for accessing the channel.

17. The system of claim 16, wherein the maintaining module includes

a module for providing for a key management server which maintains the key for

the channel; and

a module for maintaining contact between each node and the key management

server.

18. The system of claim 14, wherein the controlling module includes:

a module to provide a key management server within the network;

a module to provide a key management control associated with each of the set of

nodes; and

a module to receive by the key management control associated with each node a

notification from the key management server including a new key for the channel.

19. The system of claim 18, wherein the receiving module receives by the key

management control associated with each node a notification from the key management

server including a new key for the channel when a new node joins the channel.

20. The system of claim 18, wherein the receiving module receives by the key

server including a new key for the channel when a node leaves the channel.

21. The system of claim 18, wherein the receiving module receives by the key

server including a new key for the channel dynamically.

22. The system of claim 13, wherein the permitting module includes a module for

providing authentication of a node with an administrative module to establish access to a

channel.

23. The system of claim 13, wherein the providing module includes a module for

controlling access to the channel.

24. The system of claim 13, wherein the providing module includes a module for

providing an administrative module to access the key from a key management server to

provide access to the channel.

25. A computer program product comprising:

a computer usable medium having computer readable code embodied therein for

processing communication within a network having a set of nodes comprising:

an establishing module configured to establish a channel for

communication within the network;

a specifying module configured to specify a key for the channel;

a providing module configured to provide access to the key by each node

in the set; and

a permitting module configured to permit communication on the channel

by the set of nodes with access to the key.

26. The computer-useable medium of claim 25, wherein the permitting module

includes a module for controlling communication on the channel using the key.

27. The computer-useable medium of claim 26, wherein the permitting module

includes a module for maintaining information identifying the set of nodes with shared

access to the key.

28. The computer-useable medium of claim 26, wherein the permitting module

includes a module for maintaining the key associated with each node for accessing the

channel.

29. The computer-useable medium of claim 28, wherein the maintaining module

includes

a module for providing for a key management server which maintains the key for

the channel; and

a module for maintaining contact between each node and the key management

server.

30. The computer-useable medium of claim 26, wherein the controlling module

includes:

a module to provide a key management server within the network;

a module to provide a key management control associated with each of the set of

nodes; and

a module to receive by the key management control associated with each node a

31. The computer-useable medium of claim 30, wherein the receiving module

receives by the key management control associated with each node a notification from the

key management server including a new key for the channel when a new node joins the

channel.

32. The computer-useab e medium of claim 30, wherein the receiving module

receives by the key manage ent control associated with each node a notification from the

key management server including a new key for the channel when a node leaves the

channel.

33. The computer-useable medium of claim 30, wherein the receiving module

key management server including a new key for the channel dynamically.

34. The computer-useable medium of claim 25, wherein the permitting module

includes a module for providing authentication of a node with an administrative module

to establish access to a channel.

35. The computer-useable medium of claim 25, wherein the providing module

includes a module for controlling access to the channel.

36. The computer-useable medium of claim 25, wherein the providing module

includes a module for providing an administrative module to access the key from a key

management server to provide access to the channel.

37. A method in a public network having a network infrastructure that is used by a

private network over which a set of nodes communicate, comprising the steps of:

establishing a channel for communication within the private network;

specifying a key for the channel;

providing access to the key by each node in the set; and

permitting communication on the channel by the set of nodes with access to the

key.

38. A computer connected to a public network infrastmcture over which a private

network operates, the private network having set of nodes, the computer comprising:

an establishing module to establish a channel for communication within the

private network;

a specifying module to specify a key for the channel;

a providing module to provide access to the key to each node in the set; and

a permitting module to permit communication on the channel by the set of nodes

with access to the key.

39. A computer program product comprising:

a computer-useable medium having computer readable code embodied therein

providing for a public network having a network infrastmcture that is used by a private

network over which a set of nodes communicate comprising:

an establishing module to establish a channel for communication within the

private network;

a specifying module to specify a key for the channel;

a providing module to provide access to the key to each node in the set; and

a permitting module to permit communication on the channel by the set of nodes

with access to the key.