homoglyph
A character that looks identical or nearly identical to another, usually from a different script, such as the Cyrillic а and the Latin a. Homoglyphs let a domain read as a famous name while being a different address.
What homoglyph does not show
Browsers often show such names in their xn-- punycode form; agents reading raw text do not get that warning.
Where homoglyph comes up on this site
- How an AI agent should verify a website before acting on itA homoglyph domain can be pixel-identical to the real one.
Related terms in Security and privacy
Where an agent, a tool or a page can be turned against its operator, and the controls that limit the damage without proving safety.
lookalike domain · incident switch · high-risk field · Indirect prompt injection · Direct prompt injection · Jailbreak · Data exfiltration · Sensitive information disclosure · Secret leakage · Insecure output handling · Excessive agency · Least privilege · Trust boundary · Input validation · Output validation · Allowlist · Denylist · SSRF · RCE · Credential scope · OAuth scope · API key · Bearer token · mTLS · Rate-limit policy · Audit log · PII · Data minimization · Purpose limitation · Retention period · Data residency · Tenant isolation · Threat model · DMARC · DMARC alignment · SPF · DKIM · MTA-STS · TLS-RPT · CAA record · DNSSEC · hard bounce
Questions about homoglyph
What is homoglyph?
A character that looks identical or nearly identical to another, usually from a different script, such as the Cyrillic а and the Latin a. Homoglyphs let a domain read as a famous name while being a different address.
What does homoglyph not show or guarantee?
Browsers often show such names in their xn-- punycode form; agents reading raw text do not get that warning.
Which area of the glossary does homoglyph belong to?
Security and privacy: Where an agent, a tool or a page can be turned against its operator, and the controls that limit the damage without proving safety.
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