Labels:text | screenshot | font OCR: TRANSMISSION AND RECEPTION OF PEM MESSAGES Plaintext message Processed message Convert message Printable to canonical form encoding Convert to required? radix 64 Generate MIC; No. attach authentification Yes Recover session key; information Encryption used? decrypt message Encryption Yes Encrypt message; No required? include key information No Generate MIC; authenticate Printable Yes message encoding Convert to required? radix 64 Convert message No from canonical form Processed message Plaintext message (a) Generic transmission diagram [b) Generic reception diagram FIGURE 1: The sender converts the message to canonical form, adds a digital signature, encrypts the result, and then converts the encrypted form into radix 64 formot. These operations are performed in reverse order by the recipient.