SiteKey

A SiteKey, in the context of web applications and particularly reCAPTCHA implementations, is a public identifier associated with a website that intends to utilize the reCAPTCHA service. This key is publicly exposed within the HTML code of the webpage. Its primary function is to allow the webpage to invoke the reCAPTCHA functionality and initiate the challenge presented to the user.

The SiteKey does not contain sensitive information that could be used to bypass security measures. Instead, it acts as a pointer that tells the reCAPTCHA service which website is requesting verification. The reCAPTCHA service then uses the SiteKey to look up associated configurations and security settings defined for that particular website.

The corresponding, but critically distinct, component is the SecretKey, which is kept server-side and never exposed to the client. The SecretKey is used to verify the user's response to the reCAPTCHA challenge, ensuring the response is legitimate and originated from the expected site.