CAPTCHA keys
When you create a CAPTCHA, a pair of keys is generated automatically: a client key and a server key. Once generated when creating a CAPTCHA, these keys never change.
The client key (client_key) is used for adding the SmartCaptcha widget to a website. This is a public key that is specified on the page hosting the widget.
The server key (server_key) is used by the website backend to get the verification results for the user request. The server key is private and should be stored in a secure location, e.g., using Yandex Lockbox.
SmartCaptcha automatically generates a one time token, i.e., a request identifier used when receiving the verification results for the user request. The token is valid for five minutes.
Warning
Never send your SmartCaptcha server key to anyone, store it unencrypted, or allow it to become public. If it did become public, create a new CAPTCHA to replace the old one.
For more information on how to get the server and client keys, see Retrieving the CAPTCHA keys.
Key format
The client key is always prefixed with ysc1_, and the server key with ysc2_. Their next 20 characters are the same.
Here are some sample keys:
client_key:ysc1_yzF85********server_key:ysc2_yzF85********