Techniques for providing security protection in wireless networks by switching modes

Techniques for security protection of a wireless network are provided. An access point is operated in a first mode. The first mode is a mode of operation that allows access to resources of a network. A security event for a client is detected while operating the access point in the first mode. Then, the access point is changed from the first mode of operation to a second mode of operation. The second mode is a restricted mode of operation that restricts access to resources of the network. Analysis may then be performed to determine if the client is an unauthorized client or valid client.

BACKGROUND OF THE INVENTION

The present invention generally relates to wireless communications and more specifically to techniques for providing security protection for access points in response to a security event.

With the advent of wireless technology and wireless networks, attacks on these networks have become more frequent. The attacks include worm propagation through a network or potential hackers that attempt to log on to an access point and infiltrate a network.

When an unauthorized client is detected, actions are taken to prevent the user from accessing the network. For example, the unauthorized client may be immediately disconnected from the access point and/or the access point may be immediately disconnected from the switch port. This is done to ensure an unauthorized client cannot access the network. This protects the network; however, false positives may occur in which clients are deemed unauthorized, but may in reality be valid clients. In these cases, the valid clients may be prevented from accessing the network, which is undesirable. Also, because the unauthorized client is disconnected from the network, it is hard to determine any information about the client, such as their identity, etc. This information may be valuable in stopping future attacks or catching a user of the unauthorized client.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

FIG. 1depicts a system100for providing security protection according to one embodiment of the present invention. As shown, access points102, client104, and network106are provided. It will be understood that any number of the components shown in system100may be provided. Additional components may be used. Components can be modified from those shown inFIG. 1.

Client104may be any computing device configured to communicate with access points102. For example, clients104may include wireless devices, such as laptop computers, cellular telephones, personal digital assistants (PDAs), Blackberry™ devices, pocket PCs, pagers, etc. Clients104can access resources on network106through access point102.

Clients104may be classified as valid clients or unauthorized clients. For example, a valid client may be any client that is authorized to access network106. An unauthorized client104may be any client where it is determined that it should not be allowed to access network106. For example, clients104that may be determined to be unauthorized include persons, devices or processes attempting undesired actions such as hackers, worms, viruses, etc. As will be described below, intrusion detection systems (IDSs), intrusion protection systems (IPSs), anomaly detection systems, etc. may be used to detect possible unauthorized clients104.

Access point102may be any access point in which a client104communicates with to access network106. For example, clients104may have to log on to access point102to access network106. Access points102include wireless gateways, routers, base stations, etc. A person skilled in the art will appreciate different examples of access points102.

Access points102are configured to form network106. Network106, in one embodiment, may be a wireless network. However, it will be understood that network106is not limited to just a wireless network and may include a wire line network also. For example, a wireless network may be connected to a wire line network.

Network106may be any network, such as a wireless local area network (WLAN), wide area network, cellular network, etc. Network106includes resources that are accessible through access point102. The resources may include data servers, such as servers where sensitive company documents are stored, Authentication, Authorization, and Accounting (AAA) servers, DNS servers, HTTP servers, FTP servers, or any other resources for an enterprise (such as a corporate network). It may be undesirable for unauthorized clients to access these resources. Accordingly, embodiments of the present invention provide security protection for the resources of network106.

In one embodiment, a security event may be determined. A client104that caused the security event may then be determined to be suspicious. The suspicious client104may be unauthorized to access network106. However, in some cases, the detection techniques may be a false positive in which suspicious client104is actually authorized to access network106. When a security event is determined, it is desirable that an investigation be done in order to determine whether the suspicious client is an unauthorized client or a valid client.

Embodiments of the present invention thus provide two modes that are used in protecting network106. The first mode is a normal mode in which access to network106is allowed through access points102. This first mode allows legitimate access to resources of network106. This mode may be a mode that access points102operate in a normal condition (i.e., resource access is allowed).

The second mode is a second level of access. This second level of access may restrict resource usage or access to resources in the network. The second mode allows lesser capability in accessing resources of network106than the first mode. For example, the traffic may be slowed down almost to a halt using quality-of-service (QOS) policies such that the suspicious client104cannot perform efficiently. Suspicious client104may not know it has been detected. For example, suspicious client104may feel that it has overloaded the network. This gives an application or a network administrator time to figure out whether suspicious client104is a valid client or unauthorized client, and any other desired information, such as where suspicious client104is located.

Also, a walled garden may be formed in which suspicious client104may only be allowed to access resources within the wall. Thus, this protects network106from suspicious client104. Also, a honeypot may be used. The honeypot is a device set to a lower security that is isolated from network resources. The honeypot may be used to collect information about suspicious client104.

When a security event is detected, instead of intentionally disconnecting suspicious client104that is responsible for the event, access point102is changed into the second mode. Changing into the second mode may not alert suspicious client104that they have been detected. The second mode is entered and analysis of the suspicious client104may be performed. If it is determined that suspicious client104is an unauthorized client, then access to network106is denied. Further analysis, as described below, may also be performed in order to determine information about the unauthorized client104. If suspicious client104is determined to be a valid client, then suspicious client104is allowed onto network106. Further, access point102may be changed back into the first mode after suspicious client104is determined to be valid.

FIG. 2depicts a simplified flowchart200of a method for providing security protection according to one embodiment of the present invention. Step202operates an access point102in a first mode. The first mode is a normal mode in which resources to network106are accessible. This is the mode in which clients104are allowed to access network106in a normal manner. For example, clients104may log on to a network using credentials.

Step204detects a security event for a suspicious client104. The security event may be detected through a variety of techniques. For example, access point102uses an agent or network monitor (i.e., intrusion detection service (IDS)/intrusion protection service (IPS), anomaly detection, etc.) to identify suspicious activity. Examples of suspicious activity may include excessive pings, too much traffic, several failed attempts at logging on to other network entities, etc.

Step206transitions valid clients104to an environment that will continue to operate in the first mode. This is so valid clients104can continue to be able to access the resources. As will be described in more detail below, valid clients104may be switched to a second access point or may be partitioned off from a suspicious client104.

Step208then changes the mode of access point102from the first mode to the second mode. The second mode provides restricted access to resources in network106or is a network isolation mode.

Step210then performs actions that are used to analyze whether the suspicious client104is an unauthorized client or valid client. For example, faults may be generated that are visible in a management station and further fed into email, a pager, etc. After this step, details about suspicious client104may be used to determine if it is a valid client. For example, a management station may automatically determine whether client104is an unauthorized client using a DNS look-up to determine an identity of suspicious client104. Also, the management station may attempt to figure out the user that logged on using suspicious client104. The identity of the user may be used to determine if the user is authorized to access the network.

Further, a network administrator may go to access point102and determine a switch in which access point102is connected and find out the details about suspicious client104. It may take time for an administrator to get the details to determine if suspicious client104is allowed to access network106. Thus, delaying a suspicious client104may be important. Accordingly, by switching into the second mode instead of disconnecting client104when a security event is determined, time for analysis is provided. In one embodiment, access is limited during this by rate limiting traffic through access point104and/or by walling off suspicious client104.

If it is determined that suspicious client104is an unauthorized client, information about suspicious client104may be captured. For example, some traffic being sent to/from client104may be captured to find out what suspicious client104is doing or any other forensic evidence may be collected. Further details on the type of analysis and techniques used to gather information will be described in more detail below.

FIG. 3depicts simplified flowchart300of a method for quarantining a suspicious client104according to one embodiment of the present invention. In this method, a suspicious client104is not moved from an access point102that suspicious client104attempted to log on to. In another embodiment, the suspicious client104may be moved to another device in which the analysis may be performed. This process will be described in more detail below.

The method assumes that access point102is operating in the first mode and a security event is detected. When a security event is detected, step302determines if clients other than the suspicious client104can be moved to another access point102. In one embodiment, it is desirable to keep a suspicious client104on the same access point102. This may make it harder for suspicious client104to determine that it has been detected as a suspicious client. In some cases, if suspicious client104knows it has been detected, it may disconnect from access point102and not allow any further information to be collected.

If the other clients104cannot be moved to another access point102, then step304performs a partitioning in order to differentiate the other clients from suspicious client104. The partitioning may include using identifiers for the other clients. For example, the identifiers may be associated with communications from the other clients104. Thus, communications with these identifiers may be allowed on network106. However, an identifier for suspicious client104may be added to communications and those communications are not passed to network106. The process then proceeds to step310.

If the other clients can be moved to another access point102, step306moves the other clients104to another access point102. Moving other users to another access point102also allows access point102to devote more resources in analyzing and identifying suspicious client104. Also, suspicious client104cannot detect the moving of other clients104to another access point102and thus still may not determine that it has been detected.

Step308changes the mode of access point102from the first mode to the second mode. Step310performs actions in order to determine if suspicious client104is an unauthorized client or a valid client.

FIG. 4depicts the system400for implementing the method described inFIG. 3according to one embodiment of the present invention. As shown, a suspicious client104-1and two other valid clients104-2are provided. Suspicious client104-1and clients104-2are communicating with access point102.

Access point102includes a detector402, transfer module404, and an analyzer406. These may be implemented in software, hardware, or any combination thereof.

Detector402is configured to detect a security event. For example, detector402may include an intrusion detection system that sends alerts when certain security events occur. When a security event is determined, transfer module404is configured to communicate with other clients104-2to facilitate moving them to another access point102-2. A person skilled in the art will appreciate how clients104-2may be moved to access point102-2. The moving of clients104-2is performed without suspicious client104-1detecting the transfer.

Analyzer406is then configured to perform actions in order to determine if client104-1is an unauthorized client or an authorized user.

FIG. 4shows a suspicious client104that is kept on an access point102. In another embodiment, a suspicious client104may be rerouted to another device. For example, a walled garden or another access point102may be used to analyze suspicious client104-1. In this case, when a security event is detected, suspicious client104-1is rerouted to a device that is operating in the second mode as described above. The device may be an access point102running in the second mode, such as a honeypot running in the second mode. The method of performing actions to analyze suspicious client104-1is then performed as described above.

The following is an example of actions that may be performed when a security event is received. As described above, the actions may be performed in order to determine if a suspicious client is unauthorized or valid. Access point102may move all other non-offending clients104to different access points102. Load balancing may be used in order to balance out the load given to other access points102.

Traffic is then slowed down on access point102. An example is when suspicious client104is transferring a large file internally using ftp from a data server to a lab. Too much traffic might set off alarms but this may be valid traffic. QOS policies may be applied to slow the traffic down, which might allow the network administrator enough time to analyze whether the traffic is valid and react accordingly. For example, access point102may be changed back to the first mode.

Access point102then captures/monitors debugging traffic for forensic logging analysis. The information can be forwarded or tunneled to an IDS/IPS/inspection engine or application for additional analysis.

Access point102may also simulate fake traffic in order to confuse suspicious client104if suspicious client104is doing passive snooping. This may keep suspicious client104on access point102.

Further, access point102and neighboring access points102may enter into a “triangulation” mode that attempts to approximate the physical location of suspicious client104. This may be performed using radio frequency (RF) power triangulation techniques. The approximate physical location would then be reported to a network administrator, stored, or identified on a network map/diagram.

If suspicious client104and its traffic are determined to be unauthorized (i.e., actively detrimental to network106, other clients or services), access point102may eventually send a disconnect signal to suspicious client104. Otherwise, access point102may maintain a connection and then stall suspicious client104until it can be physically located. If suspicious client104is determined to be a valid client, then access point102can go back to the first mode.

Embodiments of the present invention provide many advantages. For example, security forensics and the probability of identifying, locating, and stopping a suspicious client104, intruder, or attack is improved. This is improved by keeping a suspicious client104on an access point102while analysis is performed in a manner that limits the ability of a client104to determine that it has been detected.

Additionally, embodiments of the present invention can limit false positives and false negatives by handling security events in a managed manner. For example, false positives may be managed by not immediately disconnecting from a suspicious client104. Rather, analysis is performed in the second mode in order to determine if the suspicious client is a non-authorized user or authorized user.

Also, embodiments of the present invention may be implemented on a centralized architecture or on an autonomous architectures.

Although the invention has been described with respect to specific embodiments thereof, these embodiments are merely illustrative, and not restrictive of the invention.

Any suitable programming language can be used to implement the routines of embodiments of the present invention including C, C++, Java, assembly language, etc. Different programming techniques can be employed such as procedural or object oriented. The routines can execute on a single processing device or multiple processors. Although the steps, operations, or computations may be presented in a specific order, this order may be changed in different embodiments. In some embodiments, multiple steps shown as sequential in this specification can be performed at the same time. The sequence of operations described herein can be interrupted, suspended, or otherwise controlled by another process, such as an operating system, kernel, etc. The routines can operate in an operating system environment or as stand-alone routines occupying all, or a substantial part, of the system processing. Functions can be performed in hardware, software, or a combination of both. Unless otherwise stated, functions may also be performed manually, in whole or in part.

A “computer-readable medium” for purposes of embodiments of the present invention may be any medium that can contain and store the program for use by or in connection with the instruction execution system, apparatus, system or device. The computer readable medium can be, by way of example only but not by limitation, a semiconductor system, apparatus, system, device, or computer memory.

Embodiments of the present invention can be implemented in the form of control logic in software or hardware or a combination of both. The control logic may be stored in an information storage medium, such as a computer-readable medium, as a plurality of instructions adapted to direct an information processing device to perform a set of steps disclosed in embodiments of the present invention. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will appreciate other ways and/or methods to implement the present invention.

Embodiments of the invention may be implemented by using a programmed general purpose digital computer, by using application specific integrated circuits, programmable logic devices, field programmable gate arrays, optical, chemical, biological, quantum or nanoengineered systems, components and mechanisms may be used. In general, the functions of embodiments of the present invention can be achieved by any means as is known in the art. Distributed, or networked systems, components and circuits can be used. Communication, or transfer, of data may be wired, wireless, or by any other means.