Secure Computing
Encyclopedia
Secure Computing Corporation, or SCC, was a public company
that developed and sold computer security
appliances and hosted services to protect users and data. McAfee
acquired the company in 2008.
The company also developed filtering systems used by governments such as Iran
and Saudi Arabia
that blocks their citizens from accessing information on the Internet.
in Minneapolis, Minnesota
. The centerpiece of SCTC was its work on security-evaluated operating system
s for the NSA. This work included the Secure Ada Target (SAT) and the Logical Coprocessing Kernel (LOCK), both designed to meet the stringent A1 level of the Trusted Computer Systems Evaluation Criteria (TCSEC).
Secure Computing morphed itself from a small defense contractor
into a commercial product vendor over the next several years. This was largely driven by the investment community, which was much less interested in purchasing security goods from defense contractors than from commercial product vendors, especially vendors in the growing Internet
space.
Secure Computing became a publicly traded company in 1995. Following the pattern of other Internet-related startups
, the stock price tripled its first day: it opened at $16 a share and closed at $48. The price peaked around $64 in the next several weeks and then collapsed over the following year or so. It ranged between roughly $3 and $20 afterward until the company was purchased by McAfee.
The company headquarters were moved to San Jose, California
in 1998, though the bulk of the workforce remained in the Twin Cities. The Roseville employees completed a move to St. Paul, Minnesota in February 2006. Several other sites now exist, largely the result of mergers (described below).
to provide challenge-response authentication
. Bosen published a computer game for the TRS-80
home computer
in 1979, called 80 Space Raiders, that used a simple challenge response mechanism for copy protection. People who used the mechanism encouraged him to repackage it for remote authentication. Bosen started Enigma Logic to do so, and filed for patents in 1982–3; a patent was issued in the United Kingdom in 1986. Ultimately, the challenge portion of the challenge response was eliminated to produce a one-time password
token similar to the SecurID
product.
Enigma Logic merged with Secure Computing Corporation in 1996.
Secure Computing acquired the SmartFilter product line by purchasing Webster Network Strategies, the producer of the WebTrack product, in 2006. The acquisition included the domain name webster.com which was eventually sold to the publishers of Webster's Dictionary
.
Shortly after acquiring the Webster/SmartFilter product, Secure Computing merged with Border Network Technologies, a Canadian company selling the Borderware firewall. Border Network Technologies boasted an excellent product and a highly developed set of sales channels; some said that the sales channels were a major inducement for the merger. Although the plan was to completely merge the Borderware product with Sidewinder, and to offer a single product to existing users of both products, this never quite succeeded. In 1998, the Borderware business unit was sold to a new company, Borderware Technologies Inc., formed by one of the original Borderware founders.
By this time, the mergers yielded a highly distributed company with an office in Minnesota
, Florida
, California
, and two or three in Ontario
. This proved unwieldy, and the company scaled back to offices in Minnesota and California.
In 2002, the company took over the Gauntlet Firewall product from Network Associates
.
In 2003, Secure Computing acquired N2H2
, the makers of the Bess web filtering package. There has been some consolidation of Bess and SmartFilter, and Bess is now referred to as "Smartfilter, Bess edition" in company literature.
An acquisition of CyberGuard was announced in August 2005 and approved in January 2006. (A year earlier, CyberGuard had attempted to acquire Secure Computing, but the proposal had been rejected). The largest merger by Secure Computing at the time, it resulted in the addition of several product lines to the company, including three classes of firewalls, content and protocol filtering systems, and an enterprise-wide management system for controlling all of those products. Several offices were also added, including CyberGuard's main facility in Deerfield Beach, Florida
, as well as the Webwasher development office in Paderborn, Germany, and a SnapGear development office in Brisbane, Australia.
In 2006, the company merged with Atlanta-based CipherTrust
, a developer of email security solutions. The merger was announced in July 2006 and completed in August 2006.
On July 30, 2008, Secure Computing announced its intention to sell the SafeWord authentication product line to Aladdin Knowledge Systems
, leaving the company with a business focused on web/mail security and firewalls.
On September 22, 2008, McAfee announced its intention to acquire Secure Computing. The combined company would form the world's largest dedicated security company at the time.
studied filtering software used by governments to block access by their citizens and found Secure Computing's SmartFilter program heavily used by both the Iranian and Saudi governments. According to Secure Computing, any use of its software in Iran is without its consent—U.S. sanctions prohibit
American companies from any dealings with Iran—and in 2005 the company said it is actively working to stop its illegal use.
In response to the company, Jonathan Zittrain
, co-director of Harvard Law School
's Berkman Center for Internet and Society, stated, "[T]he fact remains that the software has been in use for an extended period of time there. And we've seen Secure Computing software turn up in more than just Iran. We've seen it in Saudi Arabia as well."
In 2001 The New York Times
reported that Secure Computing was one of ten companies competing for the Saudi government's contract for software to block its citizens access to websites it deemed offensive. The company already had a deal with the Saudis that was due to expire in 2003. In its defense, Secure Computing has always stated that it can not control how customers use a product once it has been sold. According to the OpenNet Initiative's 2007 report, the Saudi government's censorship "most extensively covers religious and social content, though sites relating to opposition groups and regional political and human rights issues are also targeted."
, a reputation system that Secure Computing obtained as part of the CipherTrust
acquisition, has become a key technology to the company, enabling all product lines with global intelligence capability based on behavioral analysis of traffic patterns from all of company's email, web and firewall devices and hosted services, as well as those of numerous OEM partners. TrustedSource derives real-time reputation scores of IPs, URLs, domains, and mail/web content based on a variety of data mining/analysis techniques, such as Support Vector Machine
, Random forest
, and Term-Frequency Inverse-Document Frequency (TFIDF) classifiers.
reputation-enabled URL filtering controls, content caching and SSL scanning capabilities.
In June 2008, Secure Computing launched Secure Web Protection Service, an in-the-cloud hosted web security service that provides a similar set of features to the Secure Web appliance, without requiring any on-premise equipment or software.
reputation-enabled anti-spam, data-leakage protection (DLP), encryption and anti-malware capabilities.
at least so to believe.
The Sidewinder firewall incorporated technical features of the high-assurance LOCK system, including Type enforcement
, a technology later applied in SELinux. However, interaction between Secure Computing and the open source
community has been spotty due to the company's ownership of patent
s related to Type enforcement. The Sidewinder never really tried to achieve an A1 TCSEC rating, but it did earn an EAL-4+ Common Criteria
rating.
Along with Sidewinder, Gauntlet had been one of the earliest application layer
firewalls; both had developed a large customer base in the United States Department of Defense
. Gauntlet was originally developed by Trusted Information Systems
(TIS) as a commercial version of the TIS Firewall Toolkit, an early open source firewall package developed under a DARPA contract.
Public company
This is not the same as a Government-owned corporation.A public company or publicly traded company is a limited liability company that offers its securities for sale to the general public, typically through a stock exchange, or through market makers operating in over the counter markets...
that developed and sold computer security
Computer security
Computer security is a branch of computer technology known as information security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to...
appliances and hosted services to protect users and data. McAfee
McAfee
McAfee, Inc. is a computer security company headquartered in Santa Clara, California, USA. It markets software and services to home users, businesses and the public sector. On August 19, 2010, electronics company Intel agreed to purchase McAfee for $7.68 billion...
acquired the company in 2008.
The company also developed filtering systems used by governments such as Iran
Internet censorship in Iran
In the first few years of the 21st century, Iran experienced a great surge in Internet usage, and, with 20 million people on the Internet, currently has the second highest percentage of its population online in the Middle East, after Israel. When initially introduced, the Internet services...
and Saudi Arabia
Communications in Saudi Arabia
Telephones - main lines in use:3,317,550 Telephones - mobile cellular:21,500,000 note:In 2004, the Saudi Telecom Company monopolization was broken by authorizing Etihad Etisalat/Mobily to compete in mobile communication, in June 2009 GO Telecom or "جو" also entered the market.Digital Radio...
that blocks their citizens from accessing information on the Internet.
Company history
In 1984, a research group called the Secure Computing Technology Center (SCTC) was formed at HoneywellHoneywell
Honeywell International, Inc. is a major conglomerate company that produces a variety of consumer products, engineering services, and aerospace systems for a wide variety of customers, from private consumers to major corporations and governments....
in Minneapolis, Minnesota
Minneapolis, Minnesota
Minneapolis , nicknamed "City of Lakes" and the "Mill City," is the county seat of Hennepin County, the largest city in the U.S. state of Minnesota, and the 48th largest in the United States...
. The centerpiece of SCTC was its work on security-evaluated operating system
Security-evaluated operating system
In computing, security-evaluated operating systems have achieved certification from an external security-auditing organization, such as a B2 or A1 CSC-STD-001-83 "Department of Defense Trusted Computer System Evaluation Criteria" or Common Criteria certification.Note that meeting a given set of...
s for the NSA. This work included the Secure Ada Target (SAT) and the Logical Coprocessing Kernel (LOCK), both designed to meet the stringent A1 level of the Trusted Computer Systems Evaluation Criteria (TCSEC).
Secure Computing morphed itself from a small defense contractor
Defense contractor
A defense contractor is a business organization or individual that provides products or services to a military department of a government. Products typically include military aircraft, ships, vehicles, weaponry, and electronic systems...
into a commercial product vendor over the next several years. This was largely driven by the investment community, which was much less interested in purchasing security goods from defense contractors than from commercial product vendors, especially vendors in the growing Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
space.
Secure Computing became a publicly traded company in 1995. Following the pattern of other Internet-related startups
Dot-com company
A dot-com company, or simply a dot-com , is a company that does most of its business on the Internet, usually through a website that uses the popular top-level domain, ".com" .While the term can refer to present-day companies, it is also used specifically to refer to companies with...
, the stock price tripled its first day: it opened at $16 a share and closed at $48. The price peaked around $64 in the next several weeks and then collapsed over the following year or so. It ranged between roughly $3 and $20 afterward until the company was purchased by McAfee.
The company headquarters were moved to San Jose, California
San Jose, California
San Jose is the third-largest city in California, the tenth-largest in the U.S., and the county seat of Santa Clara County which is located at the southern end of San Francisco Bay...
in 1998, though the bulk of the workforce remained in the Twin Cities. The Roseville employees completed a move to St. Paul, Minnesota in February 2006. Several other sites now exist, largely the result of mergers (described below).
Mergers and acquisitions
Secure Computing consists of several merged units, one of the oldest being Enigma Logic, Inc., which was started around 1982. Bob Bosen, the founder, claims to have created the first security tokenSecurity token
A security token may be a physical device that an authorized user of computer services is given to ease authentication...
to provide challenge-response authentication
Challenge-response authentication
In computer security, challenge-response authentication is a family of protocols in which one party presents a question and another party must provide a valid answer to be authenticated....
. Bosen published a computer game for the TRS-80
TRS-80
TRS-80 was Tandy Corporation's desktop microcomputer model line, sold through Tandy's Radio Shack stores in the late 1970s and early 1980s. The first units, ordered unseen, were delivered in November 1977, and rolled out to the stores the third week of December. The line won popularity with...
home computer
Home computer
Home computers were a class of microcomputers entering the market in 1977, and becoming increasingly common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user...
in 1979, called 80 Space Raiders, that used a simple challenge response mechanism for copy protection. People who used the mechanism encouraged him to repackage it for remote authentication. Bosen started Enigma Logic to do so, and filed for patents in 1982–3; a patent was issued in the United Kingdom in 1986. Ultimately, the challenge portion of the challenge response was eliminated to produce a one-time password
One-time password
A one-time password is a password that is valid for only one login session or transaction. OTPs avoid a number of shortcomings that are associated with traditional passwords. The most important shortcoming that is addressed by OTPs is that, in contrast to static passwords, they are not vulnerable...
token similar to the SecurID
SecurID
SecurID, now known as RSA SecurID, is a mechanism developed by Security Dynamics for performing two-factor authentication for a user to a network resource.- Description :...
product.
Enigma Logic merged with Secure Computing Corporation in 1996.
Secure Computing acquired the SmartFilter product line by purchasing Webster Network Strategies, the producer of the WebTrack product, in 2006. The acquisition included the domain name webster.com which was eventually sold to the publishers of Webster's Dictionary
Webster's Dictionary
Webster's Dictionary refers to the line of dictionaries first developed by Noah Webster in the early 19th century, and also to numerous unrelated dictionaries that added Webster's name just to share his prestige. The term is a genericized trademark in the U.S.A...
.
Shortly after acquiring the Webster/SmartFilter product, Secure Computing merged with Border Network Technologies, a Canadian company selling the Borderware firewall. Border Network Technologies boasted an excellent product and a highly developed set of sales channels; some said that the sales channels were a major inducement for the merger. Although the plan was to completely merge the Borderware product with Sidewinder, and to offer a single product to existing users of both products, this never quite succeeded. In 1998, the Borderware business unit was sold to a new company, Borderware Technologies Inc., formed by one of the original Borderware founders.
By this time, the mergers yielded a highly distributed company with an office in Minnesota
Minnesota
Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...
, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, and two or three in Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
. This proved unwieldy, and the company scaled back to offices in Minnesota and California.
In 2002, the company took over the Gauntlet Firewall product from Network Associates
McAfee
McAfee, Inc. is a computer security company headquartered in Santa Clara, California, USA. It markets software and services to home users, businesses and the public sector. On August 19, 2010, electronics company Intel agreed to purchase McAfee for $7.68 billion...
.
In 2003, Secure Computing acquired N2H2
N2H2
N2H2 may refer to:* N2H2, Diazene, a chemical compound* Secure Computing...
, the makers of the Bess web filtering package. There has been some consolidation of Bess and SmartFilter, and Bess is now referred to as "Smartfilter, Bess edition" in company literature.
An acquisition of CyberGuard was announced in August 2005 and approved in January 2006. (A year earlier, CyberGuard had attempted to acquire Secure Computing, but the proposal had been rejected). The largest merger by Secure Computing at the time, it resulted in the addition of several product lines to the company, including three classes of firewalls, content and protocol filtering systems, and an enterprise-wide management system for controlling all of those products. Several offices were also added, including CyberGuard's main facility in Deerfield Beach, Florida
Deerfield Beach, Florida
Deerfield Beach is a city in Broward County, Florida, USA. The city is named for the numerous deer that once roamed the area. As of the 2010 United States Census, the population was 75,018...
, as well as the Webwasher development office in Paderborn, Germany, and a SnapGear development office in Brisbane, Australia.
In 2006, the company merged with Atlanta-based CipherTrust
Ciphertrust
CipherTrust was an anti-spam email software company based in Alpharetta, GA , although they had offices around the world. Since August 2006 it is part of Secure Computing Corp, which was acquired by McAfee in 2008. The company was co-founded by Jay Chaudhry and Lawrence Hughes...
, a developer of email security solutions. The merger was announced in July 2006 and completed in August 2006.
On July 30, 2008, Secure Computing announced its intention to sell the SafeWord authentication product line to Aladdin Knowledge Systems
Aladdin Knowledge Systems
Aladdin Knowledge Systems was a company that produced software for digital rights management and Internet security. The company was by SafeNet Inc, in 2009. Its corporate headquarters are located in Belcamp...
, leaving the company with a business focused on web/mail security and firewalls.
On September 22, 2008, McAfee announced its intention to acquire Secure Computing. The combined company would form the world's largest dedicated security company at the time.
Use of company products for governmental censorship
The OpenNet InitiativeOpenNet Initiative
The OpenNet Initiative is a joint project whose goal is to monitor and report on internet filtering and surveillance practices by nations. The project employs a number of technical means, as well as an international network of investigators, to determine the extent and nature of government-run...
studied filtering software used by governments to block access by their citizens and found Secure Computing's SmartFilter program heavily used by both the Iranian and Saudi governments. According to Secure Computing, any use of its software in Iran is without its consent—U.S. sanctions prohibit
Sanctions against Iran
This article outlines economic, trade, scientific and military sanctions against Iran, which have been imposed by the U.S. government, or under U.S. pressure by the international community through the United Nations Security Council...
American companies from any dealings with Iran—and in 2005 the company said it is actively working to stop its illegal use.
In response to the company, Jonathan Zittrain
Jonathan Zittrain
Jonathan L. Zittrain is a US professor of Internet law at Harvard Law School and the Harvard Kennedy School, a professor of computer science at the Harvard School of Engineering and Applied Sciences, and a faculty co-director of Harvard's Berkman Center for Internet & Society...
, co-director of Harvard Law School
Harvard Law School
Harvard Law School is one of the professional graduate schools of Harvard University. Located in Cambridge, Massachusetts, it is the oldest continually-operating law school in the United States and is home to the largest academic law library in the world. The school is routinely ranked by the U.S...
's Berkman Center for Internet and Society, stated, "[T]he fact remains that the software has been in use for an extended period of time there. And we've seen Secure Computing software turn up in more than just Iran. We've seen it in Saudi Arabia as well."
In 2001 The New York Times
The New York Times
The New York Times is an American daily newspaper founded and continuously published in New York City since 1851. The New York Times has won 106 Pulitzer Prizes, the most of any news organization...
reported that Secure Computing was one of ten companies competing for the Saudi government's contract for software to block its citizens access to websites it deemed offensive. The company already had a deal with the Saudis that was due to expire in 2003. In its defense, Secure Computing has always stated that it can not control how customers use a product once it has been sold. According to the OpenNet Initiative's 2007 report, the Saudi government's censorship "most extensively covers religious and social content, though sites relating to opposition groups and regional political and human rights issues are also targeted."
TrustedSource reputation system
TrustedSourceTrustedSource
TrustedSource is an Internet reputation system originally developed by CipherTrust and now owned by McAfee. It provides reputation scores for Internet identities, such as IP addresses, URLs, domains, and email/web content....
, a reputation system that Secure Computing obtained as part of the CipherTrust
Ciphertrust
CipherTrust was an anti-spam email software company based in Alpharetta, GA , although they had offices around the world. Since August 2006 it is part of Secure Computing Corp, which was acquired by McAfee in 2008. The company was co-founded by Jay Chaudhry and Lawrence Hughes...
acquisition, has become a key technology to the company, enabling all product lines with global intelligence capability based on behavioral analysis of traffic patterns from all of company's email, web and firewall devices and hosted services, as well as those of numerous OEM partners. TrustedSource derives real-time reputation scores of IPs, URLs, domains, and mail/web content based on a variety of data mining/analysis techniques, such as Support Vector Machine
Support vector machine
A support vector machine is a concept in statistics and computer science for a set of related supervised learning methods that analyze data and recognize patterns, used for classification and regression analysis...
, Random forest
Random forest
Random forest is an ensemble classifier that consists of many decision trees and outputs the class that is the mode of the class's output by individual trees. The algorithm for inducing a random forest was developed by Leo Breiman and Adele Cutler, and "Random Forests" is their trademark...
, and Term-Frequency Inverse-Document Frequency (TFIDF) classifiers.
Web Security products
The company's flagship web security product line is the Secure Web appliance (formerly known as Webwasher). It provides Anti-Malware protection, TrustedSourceTrustedSource
TrustedSource is an Internet reputation system originally developed by CipherTrust and now owned by McAfee. It provides reputation scores for Internet identities, such as IP addresses, URLs, domains, and email/web content....
reputation-enabled URL filtering controls, content caching and SSL scanning capabilities.
In June 2008, Secure Computing launched Secure Web Protection Service, an in-the-cloud hosted web security service that provides a similar set of features to the Secure Web appliance, without requiring any on-premise equipment or software.
Mail Security products
The company's flagship email security product line is the Secure Mail appliance (formerly known as IronMail). It provides TrustedSourceTrustedSource
TrustedSource is an Internet reputation system originally developed by CipherTrust and now owned by McAfee. It provides reputation scores for Internet identities, such as IP addresses, URLs, domains, and email/web content....
reputation-enabled anti-spam, data-leakage protection (DLP), encryption and anti-malware capabilities.
at least so to believe.
Secure Firewalls
The company's flagship firewall product is now called McAfee Firewall Enterprise (formerly known as Sidewinder). Over the years, Secure Computing (and it's antecedent organizations) has offered the following major lines of firewall products:- Firewall Enterprise (Sidewinder) – historically based on SecureOS, the company's derivative of BSDi (previously BSD/OSBSD/OSBSD/OS was a proprietary version of the BSD operating system developed by Berkeley Software Design, Inc. ....
), but now based on FreeBSDFreeBSDFreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
. - Secure Firewall Reporter
- Secure Firewall CommandCenter
- CyberGuard
- Secure SnapGear – embedded system based on μClinuxUClinuxμClinux stands for "MicroController Linux," and is pronounced "you-see-Linux" as explained on the website, not the way the Greek letter mu is normally pronounced. It was a fork of the Linux kernel for microcontrollers without a memory management unit...
- Classic – built on UnixWareUnixWareUnixWare is a Unix operating system maintained by The SCO Group . UnixWare is typically deployed as a server rather than desktop. Binary distributions of UnixWare are available for x86 architecture computers. It was originally released by Univel, a jointly owned venture of AT&T's Unix System...
- TSP (Total Stream Protection) – built on LinuxLinuxLinux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
- Secure SnapGear – embedded system based on μClinux
- Borderware – sold off, as noted previously
- SecureZone – discontinued
- Firewall for NTWindows NTWindows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix. It was intended to complement...
– discontinued - Gauntlet – built on Solaris, nearly phased out
The Sidewinder firewall incorporated technical features of the high-assurance LOCK system, including Type enforcement
Type enforcement
The concept of type enforcement in the field of information technology is related to access control. Implementing TE, gives priority to “mandatory access control” over “discretionary access control” . Access clearance is first given to a subject accessing objects based on rules defined in an...
, a technology later applied in SELinux. However, interaction between Secure Computing and the open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
community has been spotty due to the company's ownership of patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
s related to Type enforcement. The Sidewinder never really tried to achieve an A1 TCSEC rating, but it did earn an EAL-4+ Common Criteria
Common Criteria
The Common Criteria for Information Technology Security Evaluation is an international standard for computer security certification...
rating.
Along with Sidewinder, Gauntlet had been one of the earliest application layer
Application layer
The Internet protocol suite and the Open Systems Interconnection model of computer networking each specify a group of protocols and methods identified by the name application layer....
firewalls; both had developed a large customer base in the United States Department of Defense
United States Department of Defense
The United States Department of Defense is the U.S...
. Gauntlet was originally developed by Trusted Information Systems
Trusted Information Systems
Trusted Information Systems was a computer security research and development company during the 1980s and 1990s, performing computer and communications security research for organizations such as NSA, DARPA, ARL, AFRL, SPAWAR, and others.TIS was founded in 1983 by NSA veteran Steve Walker, and at...
(TIS) as a commercial version of the TIS Firewall Toolkit, an early open source firewall package developed under a DARPA contract.
External links
- Secure Computing Corporation web site
- Cost Profile of a Highly Assured, Secure Operating System, an overview of the LOCK system.
- Is Your Network Secure?, an early Byte magazine article on the Sidewinder firewall.