A signature permit is a permission that an application or website can request from your crypto wallet. The signature uses the private key of the wallet address to sign the data presented.
Signatures can be used for many things such as proving wallet ownership, transferring tokens, swapping tokens without cost, and many other actions that may be taken by a wallet.
Wallet owners must take special care with any signature requests they see in their wallets. A single signature can trigger many actions, and it can be easy to sign malicious data without realizing it.
Therefore, it is extremely important to confirm that you are on a trusted site when signing data. Visit the website and confirm that it is the product or service you intended to interact with before signing any request.
When a signature is requested by an app, your wallet may or may not be able to decode the request and verify what permissions the signature is granting.
Even when the request can be decoded, it is important to confirm that it is performing the actions that you expect.
When signature data is not decoded, this is referred to as blind-signing. Blind signing can cause loss or open your wallet up to risk, since you cannot verify the actions it will be taking.
In summary: when a signature is requested from a wallet, there are endless possibilities for what this data could do. Verifying anything possible is best for a wallet's safety. If you see data that is not decoded, it is strongly recommended that you verify that the website is trusted.