Asymmetric Encryption uses two distinct, yet related keys. One key, the Public Key, is used for encryption and the other, the Private Key, is for decryption.The Private Key is intended to be private so that only the authenticated recipient can decrypt the message.As of now zoho only allows developers to encrypt the data with only one key with AES encrypt function which is symmetric Encryption which intern uses only one key but when dealing with banking and other service's the providers expect their clients data's to be Asymmetrically encrypted with private ,public key for security purposes.As we move towards secure data transactions nowadays,other service providers allover the globe expect zoho to incorporate this feature as soon as possible which makes the integration possible.