A keyboarded a mix of private and public text composing a source-text document is submitted through an encryption adapter intersituated in a data signal link between the keyboard and a computer system. A user selects and obfuscates the private text character portions with surrogate cloak characters in concurrent alternation with direct entry of the public text characters. A resultant protected document's data signal is safeguarded for editing and data storage without revelation of the private text content. The protected document is sufficiently secure for submission into a cloud computing environment and is immune to key-entry tracking malware. Clandestine hacking of residual data remaining in the computer firmware is negated in interpretative value by enabling the user's selective obfuscation of the source-text document's private text character content with surrogate cloak characters prior to entry into the computer system's keyboard input port.