Taken from the PayPal website:
Beginning in early 2016, PayPal will introduce a number of security-related product updates.
These updates are part of an industry-wide initiative to improve security standards. Some of these updates, like the TLS upgrade, are mandated by the PCI Security Council and are required by every website that transmits or processes cardholder data.
Merchants and developers may have to update their integrations in order to be in compliance and ensure that their applications continue to function as expected. [Read more…]