STRIDE model

STRIDE is a model for identifying computer security threats^[1] developed by Praerit Garg and Loren Kohnfelder at Microsoft.^[2] It provides a mnemonic for security threats in six categories.^[3]

The threats are:

• Spoofing
• Tampering
• Repudiation
• Information disclosure (privacy breach or data leak)
• Denial of service
• Elevation of privilege^[4]

The STRIDE was initially created as part of the process of threat modeling. STRIDE is a model of threats, used to help reason and find threats to a system. It is used in conjunction with a model of the target system that can be constructed in parallel. This includes a full breakdown of processes, data stores, data flows, and trust boundaries.^[5]

Today it is often used by security experts to help answer the question "what can go wrong in this system we're working on?"

Each threat is a violation of a desirable property for a system:

Threat	Desired property	Threat Definition
Spoofing	Authenticity	Pretending to be something or someone other than yourself
Tampering	Integrity	Modifying something on disk, network, memory, or elsewhere
Repudiation	Non-repudiability	Claiming that you didn't do something or were not responsible; can be honest or false
Information disclosure	Confidentiality	Someone obtaining information they are not authorized to access
Denial of service	Availability	Exhausting resources needed to provide service
Elevation of privilege	Authorization	Allowing someone to do something they are not authorized to do

Notes on the threats

Repudiation is unusual because it's a threat when viewed from a security perspective, and a desirable property of some privacy systems, for example, Goldberg's "Off the Record" messaging system. This is a useful demonstration of the tension that security design analysis must sometimes grapple with.

Elevation of privilege is often called escalation of privilege, or privilege escalation. They are synonymous.

See also

• Attack tree – another approach to security threat modeling, stemming from dependency analysis
• Cyber security and countermeasure
• DREAD – a classification system for security threats
• OWASP – an organization devoted to improving web application security through education
• CIA also known as AIC^[6][7] – another mnemonic for a security model to build security in IT systems