The toy example keeps its boundary narrow.

highlighted = computed this step

What this toy model checks

The trust boundary parses one Set-Cookie response, parses one later request, and checks that the returned label matches.

recompute cookie round trip\text{recompute cookie round trip}
Cookie honesty boundaryThe later request and cookie match rows are recomputed from pinned bytes.Cookie honesty boundary - Set-Cookie sid=7 returns as Cookie sid=7sectionnamevaluecheckstatusstatus200 OKokheaderSet-Cookiesid=7; Path=/parsedcookienamesidlabelcookievalue7labelcookiePath/pinnedheaderContent-Length0no bodyrequest linemethodGETparsedrequest linepath/cartparsedrequest lineversionHTTP/1.1parsedheaderHostshop.exampleexactheaderCookiesid=7sent backcheckSet-Cookiesid=7from responsecheckCookiesid=7from requestcheckPath/pinnedcheckmatchyessame labelchecksent body bytes0empty body

Honesty boundary

NOTE: toy HTTP cookie round trip only; not login, authentication, sessions, tracking, privacy law, SameSite, Secure, HttpOnly, expiration, domain matching, multiple cookies, storage policy, browser behavior details, CSRF, or production security config.

toy cookie label only\text{toy cookie label only}
Cookie honesty boundaryThe later request and cookie match rows are recomputed from pinned bytes.Cookie honesty boundary - Set-Cookie sid=7 returns as Cookie sid=7sectionnamevaluecheckstatusstatus200 OKokheaderSet-Cookiesid=7; Path=/parsedcookienamesidlabelcookievalue7labelcookiePath/pinnedheaderContent-Length0no bodyrequest linemethodGETparsedrequest linepath/cartparsedrequest lineversionHTTP/1.1parsedheaderHostshop.exampleexactheaderCookiesid=7sent backcheckSet-Cookiesid=7from responsecheckCookiesid=7from requestcheckPath/pinnedcheckmatchyessame labelchecksent body bytes0empty body

No client compute

The page shows already validated rows. It does not store cookies or run browser behavior.

static validated rows\text{static validated rows}
Cookie honesty boundaryThe later request and cookie match rows are recomputed from pinned bytes.Cookie honesty boundary - Set-Cookie sid=7 returns as Cookie sid=7sectionnamevaluecheckstatusstatus200 OKokheaderSet-Cookiesid=7; Path=/parsedcookienamesidlabelcookievalue7labelcookiePath/pinnedheaderContent-Length0no bodyrequest linemethodGETparsedrequest linepath/cartparsedrequest lineversionHTTP/1.1parsedheaderHostshop.exampleexactheaderCookiesid=7sent backcheckSet-Cookiesid=7from responsecheckCookiesid=7from requestcheckPath/pinnedcheckmatchyessame labelchecksent body bytes0empty body

Summary

A Set-Cookie response header can become a Cookie request header later.

header returns later\text{header returns later}
Cookie honesty boundaryThe later request and cookie match rows are recomputed from pinned bytes.Cookie honesty boundary - Set-Cookie sid=7 returns as Cookie sid=7sectionnamevaluecheckstatusstatus200 OKokheaderSet-Cookiesid=7; Path=/parsedcookienamesidlabelcookievalue7labelcookiePath/pinnedheaderContent-Length0no bodyrequest linemethodGETparsedrequest linepath/cartparsedrequest lineversionHTTP/1.1parsedheaderHostshop.exampleexactheaderCookiesid=7sent backcheckSet-Cookiesid=7from responsecheckCookiesid=7from requestcheckPath/pinnedcheckmatchyessame labelchecksent body bytes0empty body