Abstract: Described are computer-based methods and apparatuses, including computer program products, for loosely-coupled encryption functionality for operating systems. A data packet is processed through one or more internet protocol stack layers to generate a processed data packet. Modified encryption information is determined that does not comprise a desired security policy for the data packet and comprises null parameter(s) and is based on encryption information that comprises the desired security policy. A message comprising data indicative of the encryption information is transmitted. An operating system is unaware of a security nature of the transmission. A null-encryption routine is executed to generate an unencrypted data packet, wherein the null-encryption routine does not encrypt the processed data packet. The unencrypted data packet is transmitted to the second computing device.