Archive: 2017-01

As organizations' critical assets have become digitized and access to information has increased, the nature and severity of threats has changed. Organizations' own personnel--insiders--now have greater ability than ever before to misuse their access to critical organizational assets. Insiders know where critical assets are, what is important, and what is valuable. Their organizations have given them authorized access to these assets and the means to compromise the confidentiality, availability, or integrity of data. As organizations rely on cyber systems to support critical missions, a malicious insider who is trying to harm an organization can do so through, for example, sabotaging a critical IT system or stealing intellectual property to benefit a new employer or a competitor. Government and industry organizations are responding to this change in the threat landscape and are increasingly aware of the escalating risks. CERT has been a widely acknowledged leader in insider threat since it began investigating the problem in 2001. The CERT Guide to Insider Threat was inducted in 2016 into the Palo Alto Networks Cybersecurity Canon, illustrating its value in helping organizations understand the risks that their own employees pose to critical assets. This blog post describes the challenge of insider threats, approaches to detection, and how machine learning-enabled software helps provide protection against this risk.

Could software save lives after a natural disaster? Meteorologists use sophisticated software-reliant systems to predict a number of pathways for severe and extreme weather events, such as hurricanes, tornados, and cyclones. Their forecasts can trigger evacuations that remove people from danger.

In this blog post, I explore key technology enablers that might pave the path toward achieving an envisioned end-state capability for software that would improve decision-making and response for disaster managers and warfighters in a modern battlefield, along with some technology deficits that we need to address along the way.

This post is also authored by Matt Sisk, the lead author of each of the tools detailed in this post (bulk query, autogeneration, and all regex).

The number of cyber incidents affecting federal agencies has continued to grow, increasing about 1,300 percent from fiscal year 2006 to fiscal year 2015, according to a September 2016 GAO report. For example, in 2015, agencies reported more than 77,000 incidents to US-CERT, up from 67,000 in 2014 and 61,000 in 2013. These incident reports come from a diverse community of federal agencies, and each may contain observations of problematic activity by a particular reporter. As a result, reports vary in content, context, and in the types of data they contain. Reports are stored in the form of 'tickets' that assign and track progress toward closure.

This blog post is the first in a two-part series on our work with US-CERT to discover and make better use of data in cyber incident tickets, which can be notoriously diverse. Specifically, this post focuses on work we have done to improve useful data extraction from cybersecurity incident reports.

The first blog entry in this series introduced the basic concepts of multicore processing and virtualization, highlighted their benefits, and outlined the challenges these technologies present. The second post addressed multicore processing, whereas the third post concentrated on virtualization via virtual machines. In this fourth post in the series, I define virtualization via containers, list its current trends, and examine its pros and cons, including its safety and security ramifications.

This posting is the third in a series that focuses on multicore processing and virtualization, which are becoming ubiquitous in software development. The first blog entry in this series introduced the basic concepts of multicore processing and virtualization, highlighted their benefits, and outlined the challenges these technologies present. The second post addressed multicore processing. This third posting concentrates on virtualization via virtual machines (VMs). Below I define the relevant concepts underlying virtualization via VMs, list its current trends, and examine its pros and cons.

As computers become more powerful and ubiquitous, software and software-based systems are increasingly relied on for business, governmental, and even personal tasks. While many of these devices and apps simply increase the convenience of our lives, some--known as critical systems--perform business- or life-preserving functionality. As they become more prevalent, securing critical systems from accidental and malicious threats has become both more important and more difficult. In addition to classic safety problems, such as ensuring hardware reliability, protection from natural phenomena, etc., modern critical systems are so interconnected that security threats from malicious adversaries must also be considered. This blog post is adapted from a new paper two colleagues (Eugene Vasserman and John Hatcliff, both at Kansas State University) and I wrote that proposes a theoretical basis for simultaneously analyzing both the safety and security of a critical system.

As part of an ongoing effort to keep you informed about our latest work, this blog post summarizes some recently published SEI reports, podcasts and webinars highlighting our work in coordinated vulnerability disclosure, scaling Agile methods, automated testing in Agile environments, ransomware, and Android app analysis. These publications highlight the latest work of SEI technologists in these areas. One SEI Special Report presents data related to DoD software projects and translated it into information that is frequently sought-after across the DoD. This post includes a listing of each publication, author(s), and links where they can be accessed on the SEI website.

In a previous post, I discussed the Pharos Binary Analysis Framework and tools to support reverse engineering of binaries with a focus on malicious code analysis. Recall that Pharos is a CERT-created framework that builds upon the ROSE compiler infrastructure developed by Lawrence Livermore National Laboratory for disassembly, control flow analysis, instruction semantics, and more. Pharos uses these features to automate common reverse engineering tasks. I'm pleased to announce that we've updated our framework on GitHub to include many new tools, improvements, and bug fixes. In this post, I'll focus on the tool-specific changes.

The first blog entry in this series introduced the basic concepts of multicore processing and virtualization, highlighted their benefits, and outlined the challenges these technologies present. This second post will concentrate on multicore processing, where I will define its various types, list its current trends, examine its pros and cons, and briefly address its safety and security ramifications.

Multicore processing and virtualization are rapidly becoming ubiquitous in software development. They are widely used in the commercial world, especially in large data centers supporting cloud-based computing, to (1) isolate application software from hardware and operating systems, (2) decrease hardware costs by enabling different applications to share underutilized computers or processors, (3) improve reliability and robustness by limiting fault and failure propagation and support failover and recovery, and (4) enhance scalability and responsiveness through the use of actual and virtual concurrency in architectures, designs, and implementation languages. Combinations of multicore processing and virtualization are also increasingly being used to build mission-critical, cyber-physical systems to achieve these benefits and leverage new technologies, both during initial development and technology refresh.

In this introductory blog post, I lay the foundation for the rest of the series by defining the basic concepts underlying multicore processing and the two main types of virtualization: (1) virtualization by virtual machines and hypervisors and (2) virtualization by containers. I will then briefly compare the three technologies and end by listing some key technical challenges these technologies bring to system and software development.

The Department of Defense is increasingly relying on biometric data, such as iris scans, gait recognition, and heart-rate monitoring to protect against both cyber and physical attacks. "Military planners, like their civilian infrastructure and homeland security counterparts, use video-linked 'behavioral recognition analytics,' leveraging base protection and counter-IED operations," according to an article in Defense Systems. Current state-of-the-art approaches do not make it possible to gather biometric data in real-world settings, such as border and airport security checkpoints, where people are in motion. This blog post presents the results of exploratory research conducted by the SEI's Emerging Technology Center to design algorithms that extract heart rate from video of non-stationary subjects in real time.

This blog post is also authored by Josh Hammerstein.

There are many opportunities for front-line soldiers to use cyber tactics to help them achieve their missions. For example, a soldier on a reconnaissance mission who enters a potentially hostile or dangerous space, such as a storefront in enemy territory, might be able to gain access to an open wireless access point in the area or exploit vulnerabilities in the building's alarm-communication system. These exploits would allow the soldier to provide indicators and warnings to other soldiers in the area about possible enemy activity and threats. Soldiers can expand their arsenal through greater awareness of specific lethal and non-lethal cyber tactics available to them. This blog post describes a new prototype tool developed at the SEI designed to help the soldier identify and exploit cyber opportunities in the physical environment.

Blockchain technology was conceived a little over ten years ago. In that short time, it went from being the foundation for a relatively unknown alternative currency to being the "next big thing" in computing, with industries from banking to insurance to defense to government investing billions of dollars in blockchain research and development. This blog post, the first of two posts about the SEI's exploration of DoD applications for blockchain, provides an introduction to this rapidly emerging technology.

When I was pursuing my master's degree in information security, two of the required classes were in cognitive psychology and human factors: one class about how we think and learn and one about how we interact with our world. Students were often less interested in these courses and preferred to focus their studies on more technical topics. I personally found them to be two of the most beneficial. In the years since I took those classes, I've worked with people in many organizations in roles where it is their job to think: security operations center (SOC) analysts, researchers, software developers, and decision makers. Many of these people are highly technical, very intelligent, and creative. In my interactions with these groups, however, the discussion rarely turns to how to think about thinking. For people whose jobs entail pulling together and interpreting data to answer a question or solve a problem (i.e. analyze), ignoring human factors and how we and others perceive, think, and remember can lead to poor outcomes. In this blog post, I will explore the importance of thinking like an analyst and introduce a framework to help guide security operations center staff and other network analysts.

The crop of Top 10 SEI Blog posts in the first half of 2017 (judged by the number of visits by our readers) represents the best of what we do here at the SEI: transitioning our knowledge to those who need it. Several of our Top 10 posts this year are from a series of posts on best practices for network security that we launched in November 2016 in the wake of the Dyn attack. In this post, we will list the Top 10 posts with an excerpt from each post as well as links to where readers can go for more information about the topics covered in the SEI blog.

As part of an ongoing effort to keep you informed about our latest work, this blog post summarizes some recently published SEI technical reports, white papers, podcasts and webinars on supply chain risk management, process improvement, network situational awareness, software architecture, network time protocol as well as a podcast interview with SEI Fellow Peter Feiler. These publications highlight the latest work of SEI technologists in these areas. This post includes a listing of each publication, author(s), and links where they can be accessed on the SEI website.

Electronic Countermeasures

During the wars in Iraq and Afghanistan, insurgents' use of improvised explosive devices (IEDs) proliferated. The United States ramped up its development of counter-IED equipment to improve standoff detection of explosives and explosive precursor components and to defeat IEDs themselves as part of a broader defense capability. One effective strategy was jamming or interrupting radio frequency (RF) communications to counter radio-controlled IEDs (RCIEDs). This approach disrupts critical parts of RF communications, making the RCIED's communication to activate ineffective, saving both warfighter and civilian lives and property. For some time now, the cyber world has also been under attack by a diffused set of enemies who improvise their own tools in many different varieties and hide them where they can do much damage. This analogy has its limitations; however, here I want to explore the idea of disrupting communications from malicious code such as ransomware that is used to lock up your digital assets, or data-exfiltration software that is used to steal your digital data.

Many organizations want to share data sets across the enterprise, but taking the first steps can be challenging. These challenges range from purely technical issues, such as data formats and APIs, to organizational cultures in which managers resist sharing data they feel they own. Data Governance is a set of practices that enable data to create value within an enterprise. When launching a data governance initiative, many organizations choose to apply best practices, such as those collected in the Data Management Association's Body of Knowledge (DAMA-BOK). While these practices define a desirable end state, our experience is that attempting to apply them broadly across the enterprise as a first step can be disruptive, expensive, and slow to deliver value. In our work with several industry and government organizations, SEI researchers have developed an incremental approach to launching data governance that delivers immediate payback. This post highlights our approach, which is based on six principles.

The future of autonomy in the military could include unmanned cargo delivery; micro-autonomous air/ground systems to enhance platoon, squad, and soldier situational awareness; and manned and unmanned teaming in both air and ground maneuvers, according to a 2016 presentation by Robert Sadowski, chief roboticist for the U.S. Army Tank Automotive Research Development and Engineering Center (TARDEC), which researches and develops advanced technologies for ground systems. One day, robot medics may even carry wounded soldiers out of battle. The system behind these feats is ROS-M, the militarized version of the Robot Operating System (ROS), an open-source set of software libraries and tools for building robot applications. In this post, I will describe the work of SEI researchers to create an environment within ROS-M for developing unmanned systems that spurs innovation and reduces development time.

The year 2016 witnessed advancements in artificial intelligence in self-driving cars, language translation, and big data. That same time period, however, also witnessed the rise of ransomware, botnets, and attack vectors as popular forms of malware attack, with cybercriminals continually expanding their methods of attack (e.g., attached scripts to phishing emails and randomization), according to Malware Byte's State of Malware report. To complement the skills and capacities of human analysts, organizations are turning to machine learning (ML) in hopes of providing a more forceful deterrent. ABI Research forecasts that "machine learning in cybersecurity will boost big data, intelligence, and analytics spending to $96 billion by 2021." At the SEI, machine learning has played a critical role across several technologies and practices that we have developed to reduce the opportunity for and limit the damage of cyber attacks. In this post--the first in a series highlighting the application of machine learning across several research projects--I introduce the concept of machine learning, explain how machine learning is applied in practice, and touch on its application to cybersecurity throughout the article.

This blog post is coauthored by Jose Morales and Angela Horneman.

On May 12, 2017, in the course of a day, the WannaCry ransomware attack infected nearly a quarter million computers. WannaCry is the latest in a growing number of ransomware attacks where, instead of stealing data, cyber criminals hold data hostage and demand a ransom payment. WannaCry was perhaps the largest ransomware attack to date, taking over a wide swath of global computers from FedEx in the United States to the systems that power Britain's healthcare system to systems across Asia, according to the New York Times. In this post, we spell out several best practices for prevention and response to a ransomware attack.

Have you ever been developing or acquiring a system and said to yourself, I can't be the first architect to design this type of system. How can I tap into the architecture knowledge that already exists in this domain? If so, you might be looking for a reference architecture. A reference architecture describes a family of similar systems and standardizes nomenclature, defines key solution elements and relationships among them, collects relevant solution patterns, and provides a framework to classify and compare. This blog posting, which is excerpted from the paper, A Reference Architecture for Big Data Systems in the National Security Domain, describes our work developing and applying a reference architecture for big data systems.

When it comes to network traffic, it's important to establish a filtering process that identifies and blocks potential cyberattacks, such as worms spreading ransomware and intruders exploiting vulnerabilities, while permitting the flow of legitimate traffic. In this post, the latest in a series on best practices for network security, I explore best practices for network border protection at the Internet router and firewall.

This post is coauthored by Carol Woody.

Software is a growing component of business and mission-critical systems. As organizations become more dependent on software, security-related risks to their organizational missions also increase. We recently published a technical note that introduces the prototype Software Assurance Framework (SAF), a collection of cybersecurity practices that programs can apply across the acquisition lifecycle and supply chain. We envision program managers using this framework to assess an acquisition program's current cybersecurity practices and chart a course for improvement, ultimately reducing the cybersecurity risk of deployed software-reliant systems. This blog post, which is excerpted from the report, presents three pilot applications of SAF.

Software design problems, often the result of optimizing for delivery speed, are a critical part of long-term software costs. Automatically detecting such design problems is a high priority for software practitioners. Software quality tools aim to automatically detect violations of common software quality rules. However, since these tools bundle a number of rules, including rules for code quality, it is hard for users to understand which rules identify design issues in particular. This blog post presents a rubric we created that quickly and accurately separates design rules from non-design rules, allowing static analysis tool users to focus on the high-value findings.

In a previous post, I addressed the testing challenges posed by non-deterministic systems and software such as the fact that the same test can have different results when repeated. While there is no single panacea for eliminating these challenges, this blog posting describes a number of measures that have proved useful when testing non-deterministic systems.

Software vulnerabilities typically cost organizations an average of $300,000 per security incident. Efforts aimed at eliminating software vulnerabilities must focus on secure coding, preventing the vulnerabilities from being deployed into production code. "Between 2010 and 2015, buffer overflows accounted for between 10-16% of publicly reported security vulnerabilities in the U.S. National Vulnerability Database each year," Microsoft researcher David Narditi wrote in a recent report. In March, the Secure Coding Team in the SEI's CERT Division published the 2016 edition of our SEI CERT C++ Coding Standard and made it freely available for download. In this blog post I will highlight some distinctive rules from the standard.

As part of an ongoing effort to keep you informed about our latest work, this blog post summarizes some recently published SEI technical reports, white papers, podcasts and webinars on software assurance, data governance, self-adaptive systems, engineering high-assurance software for distributed adaptive real-time (DART) systems, technical debt, and automating malware collection and analysis. These publications highlight the latest work of SEI technologists in these areas. This post includes a listing of each publication, author(s), and links where they can be accessed on the SEI website.

The network time protocol (NTP) synchronizes the time of a computer client or server to another server or within a few milliseconds of Coordinated Universal Time (UTC). NTP servers, long considered a foundational service of the Internet, have more recently been used to amplify large-scale Distributed Denial of Service (DDoS) attacks. While 2016 did not see a noticeable uptick in the frequency of DDoS attacks, the last 12 months have witnessed some of the largest DDoS attacks, according to Akamai's State of the Internet/Security report. One issue that attackers have exploited is abusable NTP servers. In 2014, there were over seven million abusable NTP servers. As a result of software upgrades, repaired configuration files, or the simple fact that ISPs and IXPs have decided to block NTP traffic, the number of abusable servers dropped by almost 99 percent in a matter months, according to a January 2015 article in ACM Queue. But there is still work to be done. It only takes 5,000 abusable NTP servers to generate a DDoS attack in the range of 50-400 Gbps. In this blog post, I explore the challenges of NTP and prescribe some best practices for securing accurate time with this protocol.

In the 2016 Cyber Security Intelligence Index, IBM found that 60 percent of all cyber attacks were carried out by insiders. One reason that insider threat remains so problematic is that organizations typically respond to these threats with negative technical incentives, such as practices that monitor employee behavior, detect and punish misbehavior, and otherwise try to force employees to act in the best interest of the organization. In contrast, this blog post highlights results from our recent research that suggests organizations need to take a more holistic approach to mitigating insider threat: one that incorporates human involvement. In particular, positive incentives can produce better balance and security for organizations by complementing traditional practices to insider threat programs. This post also presents three practices to increase positive incentives that organizations can use to reduce insider threat.

As cyber-physical systems continue to proliferate, the ability of cyber operators to support armed engagements (kinetic missions) will be critical for the Department of Defense (DoD) to maintain a technological advantage over adversaries. However, current training for cyber operators focuses entirely on the cyber aspect of operations and ignores the realities and constraints of supporting a larger mission. Similarly, kinetic operators largely think of cyber capabilities as a strategic, rather than a tactical resource, and are untrained in how to leverage the capabilities cyber operators can provide. In this blog post, I present Cyber Kinetic Effects Integration, also known as CKEI, which is a program developed at the SEI's CERT Division that allows the training of combined arms and cyber engagements in a virtual battlefield.

Since its debut on Jeopardy in 2011, IBM's Watson has generated a lot of interest in potential applications across many industries. I recently led a research team investigating whether the Department of Defense (DoD) could use Watson to improve software assurance and help acquisition professionals assemble and review relevant evidence from documents. As this blog post describes, our work examined whether typical developers could build an IBM Watson application to support an assurance review.

Distributed denial-of-service (DDoS) attacks have been dominating the IT security headlines. A flurry of reporting followed the September 2016 attack on the computer security reporter Brian Krebs's web site KrebsonSecurity when he reported attack traffic that was at the unprecedented scale of gigabytes per second. In November, my colleague Rachel Kartch wrote "DDOS Attacks: Four Best Practices for Prevention and Response," outlining what we can do to defend against these attacks. In this blog post, I tell the story of the Mirai powered botnet that's been harnessed in some of these recent attacks and which has also received its own share of press. My purpose is to explore the vulnerabilities that Mirai exploits and describe some simple practices that could help transform our Internet devices to mitigate the risk posed by botnets.

First responders, search-and-rescue teams, and military personnel often work in "tactical edge" environments defined by limited computing resources, rapidly changing mission requirements, high levels of stress, and limited connectivity. In these tactical edge environments, software applications that enable tasks such as face recognition, language translation, decision support, and mission planning and execution are critical due to computing and battery limitations on mobile devices. Our work on tactical cloudlets addresses some of these challenges by providing a forward-deployed platform for computation offload and data staging (see previous posts).

When establishing communication between two nodes--such as a mobile device and a tactical cloudlet in the field--identification, authentication, and authorization provide the information and assurances necessary for the nodes to trust each other (i.e., mutual trust). A common solution for establishing trust is to create and share credentials in advance and then use an online trusted authority to validate the credentials of the nodes. The tactical environments in which first responders, search-and-rescue, and military personnel operate, however, do not consistently provide access to that online authority or certificate repository because they are disconnected, intermittent, limited (DIL). This blog post, excerpted from the recently published IEEE paper "Establishing Trusted Identities in Disconnected Edge Environments"--I coauthored this paper with Sebastián Echeverría, Dan Klinedinst, Keegan Williams--presents a solution for establishing trusted identities in disconnected environments based on secure key generation and exchange in the field, as well as an evaluation and implementation of the solution.

The prevalence of Agile methods in the software industry today is obvious. All major defense contractors in the market can tell you about their approaches to implementing the values and principles found in the Agile Manifesto. Published frameworks and methodologies are rapidly maturing, and a wave of associated terminology is part of the modern lexicon. We are seeing consultants feuding on Internet forums as well, with each one claiming to have the "true" answer for what Agile is and how to make it work in your organization. The challenge now is to scale Agile to work in complex settings with larger teams, larger systems, longer timelines, diverse operating environments, and multiple engineering disciplines. I recently explored the issues surrounding scaling Agile within the Department of Defense (DoD) with Mary Ann Lapham, Suzanne Miller, Eileen Wrubel, and Peter Capell. This blog post, an excerpt of our recently published technical note Scaling Agile Methods for Department of Defense Programs, presents five perspectives on scaling Agile from leading thinkers in the field including Scott Ambler, Steve Messenger, Craig Larman, Jeff Sutherland, and Dean Leffingwell.

Interest in Agile and lightweight development methods in the software development community has become widespread. Our experiences with the application of Agile principles have therefore become richer. In my blog post, Toward Agile Strategic Planning, I wrote about how we can apply Agile principles to strategic planning. In this blog post, I apply another Agile concept, technical debt, to another organizational excellence issue. Specifically I explore whether organizational debt is accrued when we implement quick organizational change, short-cutting what we know to be effective change management methods. Since I started considering this concept, Steve Blank wrote a well-received article about organizational debt in the context of start-up organizations. In this post, I describe organizational debt in the context of change management and describe some effects of organizational debt we are seeing with our government clients.

The Domain Name System (DNS) is an essential component of the Internet, a virtual phone book of names and numbers, but we rarely think about it until something goes wrong. As evidenced by the recent distributed denial of service (DDoS) attack against Internet performance management company Dyn, which temporarily wiped out access to websites including Amazon, Paypal, Reddit, and the New York Times for millions of users down the Eastern Seaboard and Europe, DNS serves as the foundation for the security and operation of internal and external network applications. DNS also serves as the backbone for other services critical to organizations including email, external web access, file sharing and voice over IP (VoIP). There are steps, however, that network administrators can take to ensure the security and resilience of their DNS infrastructure and avoid security pitfalls. In this blog post, I outline six best practices to design a secure, reliable infrastructure and present an example of a resilient organizational DNS.

As part of an ongoing effort to keep you informed about our latest work, this blog post summarizes some recently published books, SEI technical reports, podcasts and webinars on insider threat, using malware analysis to identify overlooked security requirements, software architecture, scaling Agile methods, best practices for preventing and responding to DDoS attacks, and a special report documenting the technical history of the SEI.

These publications highlight the latest work of SEI technologists in these areas. This post includes a listing of each publication, author(s), and links where they can be accessed on the SEI website.

Federal agencies and other organizations face an overwhelming security landscape. The arsenal available to these organizations for securing software includes static analysis tools, which search code for flaws, including those that could lead to software vulnerabilities. The sheer effort required by auditors and coders to triage the large number of potential code flaws typically identified by static analysis can hijack a software project's budget and schedule. Auditors need a tool to classify alerts and to prioritize some of them for manual analysis. As described in my first post in this series, I am leading a team on a research project in the SEI's CERT Division to use classification models to help analysts and coders prioritize which vulnerabilities to address. In this second post, I will detail our collaboration with three U.S. Department of Defense (DoD) organizations to field test our approach. Two of these organizations each conduct static analysis of approximately 100 million lines of code (MLOC) annually.

By Will Klieber
CERT Secure Coding Team

This blog post is co-authored by Will Snavely.

Finding violations of secure coding guidelines in source code is daunting, but fixing them is an even greater challenge. We are creating automated tools for source code transformation. Experience in examining software bugs reveals that many security-relevant bugs follow common patterns (which can be automatically detected) and that there are corresponding patterns for repair (which can be performed by automatic program transformation). For example, integer overflow in calculations related to array bounds or indices is almost always a bug. While static analysis tools can help, they typically produce an enormous number of warnings. Once an issue has been identified, teams are only able to eliminate a small percentage of the vulnerabilities identified. As a result, code bases often contain an unknown number of security bug vulnerabilities. This blog post describes our research in automated code repair, which can eliminate security vulnerabilities much faster than the existing manual process and at a much lower cost. While this research focuses to the C programming language, it applies to other languages as well.

Many system and software developers and testers, especially those who have primarily worked in business information systems, assume that systems--even buggy systems--behave in a deterministic manner. In other words, they assume that a system or software application will always behave in exactly the same way when given identical inputs under identical conditions. This assumption, however, is not always true. While this assumption is most often false when dealing with cyber-physical systems, new and even older technologies have brought various sources of non-determinism, and this has significant ramifications on testing. This blog post, the first in a series, explores the challenges of testing in a non-deterministic world.