In Denodo, you can integrate the HP Voltage by creating a custom function for encryption and decryption using [Denodo 4E plugin](https://community.denodo.com/docs/html/browse/7.0/denodo4e/index) and deploy the custom function in the Virtual Dataport. For creating a custom function, you can have a look at section [Developing Custom Functions](https://community.denodo.com/docs/html/browse/7.0/vdp/developer/developing_extensions/developing_custom_functions/developing_custom_functions).
Besides that, you can also utilize Denodo Connect’s library for implementing encryption and decryption by downloading [Denodo XtraFuncs](https://support.denodo.com/resources/denodo-connect/list/Denodo%207.0) from the Denodo Support Site. For more information, you can refer to the [Denodo XtraFuncs - User Manual](https://community.denodo.com/docs/html/document/denodoconnects/7.0/Denodo%20XtraFuncs%20-%20User%20Manual).
Hope this helps!