Switching authentication and encryption of content between keys based on a key availability assurance value

A device, comprising:

• a processor;
• and
• a memory that stores executable instructions that, when executed by the processor,
• perform the following operations:
• receiving a first and a second decryption key from a key source, wherein an activation time of a second encryption key causes the first and the second decryption keys to be concurrently available for decryption, for a time interval;
• decrypting, during the time interval, a content item received from a content delivery device by employing the first decryption key, wherein the content item is encrypted using a first encryption key;
• and
• decrypting, during the time interval, the content item received from the content delivery device by employing the second decryption key, wherein the decrypting by employing the second decryption key is caused by the content delivery device changing encryption of the content item from the first encryption key to the second encryption key, based on an assurance value received by the content delivery device from the key source.