What is Munchkin API Private key used for?

[Gaurav]

I wanted to know the uses of Munchkin API private key

[Raghav_Chugh]

This will help you

https://nation.marketo.com/t5/Product-Discussions/What-should-I-use-as-my-Munkchin-API-private-key/m...

[SanfordWhiteman]

It's used only to create hashes for the Munchkin API Associate Lead function. Since this function is deprecated, if you're not already using it you have no use for the key. Eventually it will be removed from Admin completely.