Apple will announce the new program at the Black Hat Security Conference in Las Vegas, which started earlier this week and continues through Thursday.
The "special" iPhones will be similar to "dev devices", including iPhones that are not as locked and which will better allow security researchers to find errors.
What makes these iPhones special? A source with knowledge of the Apple announcement said that they would essentially be "dev devices." Think of them as iPhones that allow the user to do much more than they could on a traditionally locked iPhone. For example, it should be possible to search for parts of the Apple operating system that are not easily accessible on a commercial iPhone. In particular, the special devices can allow hackers to stop the processor and inspect the memory for vulnerabilities. This will allow them to see what happens at the code level when trying an attack on iOS code.
The iPhones will not be identical to the developer iPhones delivered to Apple's internal staff, since they will not be as open. They are described as "small" versions of the Forbes developer units with security researchers who are unlikely to be able to decrypt the iPhone's firmware.
iPhone prototypes created for Apple's internal staff are popular with security researchers and hackers and can fetch quite a bit of money, as mentioned in a report earlier this year from Motherboard . The iPhones are described as "pre-jailbroken devices" and are valuable because they can be used to find vulnerabilities both by those with good intentions and those with bad intentions.
Releasing a similar device to security researchers participating in the bug-bounty program might allow Apple to detect serious bugs, leading to faster fixes.
Apple is also planning to announce a new macOS bounty program, which will reward people who find and report security vulnerabilities in macOS.
Apple's announcements may come on Thursday, and that's when Ivan Krstić, Apple's chief of technology, will offer a "Behind the Scenes" appearance on iOS and macOS.