Knowledge.

Phishing

A fraud attempt by email, text message or messenger that aims to get you to reveal credentials or open malicious attachments.

Smishing and vishing

Phishing by text message (smishing) and by phone call (vishing). Typical examples are fake parcel services, banks or support staff who push you to act fast.

MFA (multi-factor authentication)

Signing in with at least two independent proofs, for example a password plus a code from an app or a security key.

Passkey

Sign-in without a password using a cryptographic key on your device, unlocked by fingerprint, face or PIN. Passkeys cannot be phished.

Password manager

Program that creates a unique, strong password for every account and stores it encrypted. You only need to remember one master password.

Ransomware

Malware that encrypts data and demands a ransom. Often the data is also stolen beforehand.

Backup (3-2-1 rule)

3 copies of your data, on two different media, one of them at another location or offline.

NAS (network attached storage)

Network storage for files, photos and backups on your own network. It should not be exposed directly to the internet and needs its own backup in another place.

RAID

Array of several drives that keeps working when one drive fails. RAID protects against hardware faults, but not against deletion, ransomware or fire. It is no substitute for a backup.

Patch management

Systematically installing security updates so that known vulnerabilities cannot be exploited.

VPN

An encrypted tunnel between a device and a network, for example for secure access to the company network while travelling.

Encryption

Makes data unreadable with a key so that only authorised people can read it. With end-to-end encryption, not even the provider can read along.

TLS and HTTPS

TLS encrypts connections on the internet and uses a certificate to check that you are talking to the right server. HTTPS is a website connection over TLS, shown by the padlock in the browser.

DNS (Domain Name System)

The phone book of the internet: it translates names like sicherheitsdenker.de into IP addresses. Manipulated DNS responses can send you to fake sites.

VLAN

A virtual network on the same hardware. It separates devices logically, for example smart home devices from the laptop.

Wi-Fi and WPA3

Wi-Fi is the wireless network for devices at home or in the office. WPA3 is its current security standard and protects passwords better against guessing than the older WPA2.

Zero Trust

An approach in which no user and no device is automatically trusted. Every access is checked, even in the internal network.

ZTNA (zero trust network access)

Access to individual applications instead of the whole network. Identity and device are checked before every connection. Seen as the successor to the classic VPN.

SASE (secure access service edge)

Networking and security from the cloud in one service: firewall, web filtering, ZTNA and secure connections for sites and mobile staff.

Least Privilege

Everyone only gets the permissions they need for their task. This limits the damage if an account is compromised.

IAM (Identity and Access Management)

Management of identities and permissions: who is who, and what may they access?

PAM (privileged access management)

Protection for accounts with extensive rights, such as administrators. Access is granted only when needed, for a limited time, and is logged.

SSO (single sign-on)

Sign in once, use many applications. Convenient and secure as long as that one sign-in is well protected, ideally with MFA.

EDR (Endpoint Detection and Response)

Software on computers and servers that detects suspicious behaviour and enables countermeasures. It goes beyond classic antivirus scanners.

XDR (Extended Detection and Response)

Extends EDR with data from email, network and cloud to detect attacks across sources.

SIEM

A system that collects log data from many sources, correlates it and raises an alarm when something is unusual.

SOC (Security Operations Center)

A team that monitors, assesses and responds to security events, in-house or as a service.

MDR (Managed Detection and Response)

A service provider takes over monitoring and response to attacks, i.e. the work of a SOC as a service.

MSSP (managed security service provider)

Service provider that takes on security tasks on an ongoing basis, such as running firewalls, monitoring in a SOC or vulnerability management.

DPIA (data protection impact assessment)

A prior assessment when data processing poses a high risk to the people concerned, for example extensive video surveillance.

GDPR (General Data Protection Regulation)

EU regulation that has governed since May 2018 how companies, associations and authorities may process personal data. It gives you rights such as access and erasure.

DPA (data processing agreement)

Contract under Art. 28 GDPR with a service provider that processes personal data on your behalf, such as a host, cloud provider or IT service provider.

TDDDG

German Telecommunications Digital Services Data Protection Act, called TTDSG until May 2024. Among other things, it governs when a website may set cookies or read data on your device.

ISO 27001

International standard for an information security management system (ISMS). Companies can be certified against it.

ISMS (information security management system)

Defined rules, roles and processes an organisation uses to plan, implement, check and continually improve information security. ISO 27001 sets out the requirements.

IT-Grundschutz

BSI methodology with standards and a compendium of concrete modules. It helps you build an appropriate security level step by step, up to certification based on ISO 27001.

NIS2

An EU directive that sets cyber security obligations for significantly more companies and sectors than before. Whether your company is affected depends on industry and size and should be checked specifically.

DORA (Digital Operational Resilience Act)

EU regulation on the digital operational resilience of the financial sector. It has applied since January 2025 to banks, insurers and their critical ICT service providers.

Cyber Resilience Act (CRA)

EU regulation setting security requirements for products with digital elements, from apps to cameras. Reporting obligations for exploited vulnerabilities have applied since September 2026, all obligations from December 2027.

IoT (Internet of Things)

Connected devices such as cameras, sensors, thermostats or door locks. Typical risks are weak default passwords and missing updates.

Smart Home

Connected home technology that can be controlled by app or voice. A separate network segment limits the damage if a device is attacked.

Matter

A cross-manufacturer standard for smart home devices with local, encrypted communication.

Zigbee

An energy-efficient wireless standard for lamps, sensors and switches. The devices form a mesh network and need a gateway.

KNX

Open standard for building automation, usually hard-wired. It controls lighting, blinds and heating. Without its own protection, KNX must not be exposed to the internet.

Thread and Z-Wave

Low-power wireless standards for smart home devices. Thread forms a mesh network and underpins many Matter devices, Z-Wave uses its own frequency below 1 GHz.

Video surveillance

The use of cameras to monitor areas. In companies, data protection requirements apply, for example on purpose, signs and storage period.

NVR (Network Video Recorder)

A device or software that records, stores and manages video streams from IP cameras.

ONVIF

An open industry standard that allows cameras and recording systems from different manufacturers to work together.

PoE (Power over Ethernet)

Power supply via the network cable. Cameras and door readers then only need one cable.

PTZ camera

Pan-tilt-zoom: a camera that can pan, tilt and zoom.

Access control system

A system that controls who may open which doors and when, by card, transponder, code or app, and can log access.

Transponder

A small radio chip in a card or key fob that communicates with a reader and thus opens doors.

RFID (MIFARE and LEGIC)

Radio technology used to read cards and transponders without contact. MIFARE and LEGIC are common systems. Older variants such as MIFARE Classic are considered easy to copy.

OSDP

A protocol for the encrypted, supervised connection between card reader and controller. Modern successor to the unencrypted Wiegand protocol.

Biometrics

Recognising people by physical traits such as fingerprint, face or iris. Convenient, but biometric data enjoys special protection and cannot be changed like a password.

Resistance class (RC)

Rating of doors and windows under EN 1627, from RC 1 to RC 6. It states how long a component withstands a break-in attempt with certain tools.

UPS (uninterruptible power supply)

Battery unit that takes over immediately during a power cut. Servers, network and cameras keep running or shut down in an orderly way.

AI (artificial intelligence)

Systems that solve tasks that would otherwise require human intelligence, for example understanding language, recognising images or preparing decisions.

Generative AI

AI that creates new content, such as text, images, audio, video or program code.

Language model (LLM)

Large language model: an AI model trained on very large amounts of text that generates text by calculating the most likely next word.

Prompt

The input or instruction you give an AI model.

Hallucination

Invented but plausible-sounding output from an AI, such as false facts, quotes or sources.

Prompt injection

An attack in which text manipulates the behaviour of a language model. Indirectly via content in emails, websites or documents that the model reads.

OWASP Top 10 for LLM

List of the ten most important security risks for applications built on language models, published by the non-profit OWASP. Number one is prompt injection.

Jailbreak

An attempt to bypass the safety rules of an AI model so that it produces unwanted content.

AI agent

A language model with tools and a planning loop that largely carries out tasks on its own, for example sorting emails or booking appointments.

MCP (Model Context Protocol)

An open standard that lets AI applications connect tools and data sources. Every connected server is a decision of trust.

RAG (Retrieval-Augmented Generation)

The model accesses a knowledge base to support answers with current or your own data.

Shadow AI

Use of AI tools without the company's approval or knowledge, often with private accounts.

Deepfake

Deceptively realistic, artificially generated or manipulated images, videos or audio recordings.

C2PA (Content Credentials)

Open standard for provenance information in images, video and audio. It records who created a file and whether AI was involved. A missing credential does not mean that something is fake.

Voice clone (voice cloning)

AI-based imitation of a voice, often from just a few seconds of audio, used for example in fraudulent calls.

Data poisoning

An attack in which training or knowledge data is manipulated so that a model responds wrongly or harmfully.

Red teaming (AI)

Targeted attack exercises on an AI system to find vulnerabilities and misbehaviour.

Bias (Verzerrung)

Systematic distortion in data or models that can lead to discriminatory results.

AI Act (KI-Verordnung)

EU Regulation 2024/1689, which regulates AI by risk: from prohibited through high-risk and transparency to minimal. It takes effect in stages.

High-risk AI

AI systems in sensitive areas such as recruitment, credit, education or critical infrastructure, for which the AI Act sets strict obligations.

AI literacy (Art. 4)

Obligation under the AI Act: providers and deployers must ensure that their staff can handle AI sufficiently well. Applies since 2 February 2025.

Provider and deployer (AI Act)

Providers develop or distribute AI systems. Deployers use them professionally. Both have different obligations depending on the risk class.

GPAI model

General-purpose AI model, such as large language models. Separate obligations have applied to them since 2 August 2025.

KI-MIG

German act implementing the AI Act, in force since 28 July 2026. It makes the Federal Network Agency the central AI supervisory authority.

Digital Omnibus (AI)

EU Regulation 2026/1744, which amends the AI Act and postpones the high-risk obligations to December 2027 and August 2028.

ISO/IEC 42001

International standard for an artificial intelligence management system. Certifiable.

NIST AI RMF

Voluntary AI risk management framework of the US institute NIST with the functions Govern, Map, Measure and Manage.

KRITIS

Critical infrastructure: facilities and institutions whose failure would significantly affect the supply of the population, such as energy, water or health.

OT (operational technology)

Technology that controls physical processes: machines, building automation, power and water. It often runs for many years without updates and needs its own isolated network.

KRITIS Umbrella Act

German law in force since 17 March 2026. It requires operators of critical facilities to take measures for their physical resilience and complements NIS2, which mainly regulates cyber security.

BSI

Federal Office for Information Security: Germany's central authority for cyber security and reporting office under NIS2.

ENISA

European Union Agency for Cybersecurity. It supports member states, publishes threat landscapes and helps develop European certification schemes.

Incident response

A structured approach to security incidents: detect, contain, eliminate, recover and learn from it.

BCM (Business Continuity Management)

Planning so that important business processes continue or restart quickly even during disruptions or crises.

RTO and RPO

RTO: what is the maximum time a system may be down? RPO: how much data loss, measured in time, is still acceptable?

MTTD and MTTR

Mean time to detect and mean time to respond: the average time until an attack is detected and until it is contained. The shorter, the smaller the damage.

Resilience

The ability to withstand disruptions, respond quickly and recover.

NDR (Network Detection and Response)

Detects attacks in network traffic and helps with the response, even for devices without agents such as IoT.

Microsegmentation

Very fine network separation down to individual servers or applications, so that attackers can hardly move laterally.

NAC and 802.1X

Network access control: devices and users must authenticate before they are allowed onto the network.

DMZ

A buffer zone between the internet and the internal network in which publicly accessible services are placed.

Firewall

Filter between networks that decides according to fixed rules which connections are allowed. Modern next-generation firewalls also recognise applications and attacks.

IDS and IPS

Intrusion detection system and intrusion prevention system. An IDS detects suspicious network traffic and reports it, an IPS also blocks it immediately.

Token

The smallest unit of text a language model works with: a word, part of a word or a character. Input and output are counted in tokens and often billed accordingly.

Context window

The amount of text a language model can take into account at once. Anything beyond that no longer feeds into the answer.

Fine-tuning

Further training of an existing model with your own example data so that it fits a task or style better.

Foundation model

A large, broadly trained model that serves as the basis for many applications. Legally often classified as a general-purpose model.

Guardrails

Technical and organisational barriers intended to prevent an AI from producing unwanted or dangerous output or actions.

Embedding

A series of numbers describing the meaning of a text or image. It can be used to find similar content, for example in RAG systems.

Vector database

Database that stores texts as number vectors (embeddings) and searches by meaning rather than exact wording. It is the memory of many RAG applications.

Open-weight model

A model whose trained weights can be downloaded publicly. This is not automatically open source, as licence and training data may differ.

System prompt

A hidden basic instruction that controls the behaviour of an AI assistant. It should not contain secrets, because it can sometimes be extracted.

Multimodal AI

AI that processes several types of input, such as text, images, audio and video.

Inference

Using a trained model to calculate an answer. The counterpart is training.

Model card

A profile of a model with purpose, training data, limitations and known risks.

Labelling obligation (Art. 50)

Obligation under the AI Act to inform people when they interact with AI and to label AI-generated content.

Malware

Umbrella term for malicious software such as viruses, worms, trojans and spyware. It steals data, spies or opens the door to attackers.

Social Engineering

Attacks on people instead of technology: perpetrators exploit trust, helpfulness or time pressure to obtain data, money or access.

CEO fraud

Scam in which criminals pose as the boss or a business partner, often with a spoofed sender address or a cloned voice, and demand an urgent payment.

Zero-Day

A vulnerability that attackers exploit before the manufacturer knows about it or provides an update.

DDoS

Distributed denial of service: many devices overload a service with requests at the same time until it is no longer reachable.

Botnet

A network of hijacked devices, often routers, cameras and other IoT devices, that attackers control remotely, for example for DDoS attacks or spam.

Supply chain attack

An attack via a supplier or service provider, for example via a manipulated software update that hits many customers at once.

Credential Stuffing

Attackers automatically try stolen username and password combinations on many services. It affects everyone who reuses passwords.

Man-in-the-Middle

An attacker places themselves unnoticed between two parties, reading or altering data, for example on an open Wi-Fi network.

Brute force

Attackers automatically try huge numbers of passwords until one works. Long passwords, lockouts after failed attempts and MFA make this practically hopeless.

Exploit

Program or method that deliberately takes advantage of a vulnerability to break into or disrupt a system. Updates close the gap the exploit needs.

Vulnerability (CVE)

Flaw in software or hardware that attackers can use to get in. Known vulnerabilities receive a CVE number so that everyone refers to the same flaw.

Penetration test

Commissioned, controlled attack by experts to find vulnerabilities before real attackers do. It ends with a report of findings and recommendations.

No match. Try a shorter search term.