UPGRADETLS STARTTLSFORCETLSOPPORTUNISTICTLS admin See author's posts Post navigation User A is writing a sensitive email message to user B outside the local network. User A has chosen to use PKI to secure his message and ensure only user B can read the sensitive email. At what layer of the OSI layer does the encryption and decryption of the message take place? Chong-lee, a forensics executive, suspects that a malware is continuously making copies of files and folders on a victim system to consume the available disk space. What type of test would confirm his claim?