Apple has revealed that the new A19 chips in the iPhone 17 series (including iPhone Air) are its first chips to support a new security feature in iOS called Memory Integrity Enforcement (MIE). This new technology is a big leap in addressing memory safety vulnerabilities, an industry-wide problem and the main attack vector used by by mercenary spyware that state-backed hackers use to spy on high-profile targets (among other advanced attacks). One key part of MIE is EMTE (Enhanced Memory Tagging Extension), a memory-safety technology that Apple co-developed with Arm, based on Arm's MTE technology. EMTE assigns a type of security key to each set of data in memory, so applications can't access memory not allocated to them. However, checking those keys can hurt performance, and the timing of the checking process can reveal signals that compromise the keys. Therefore, Apple designed its new A19 chips with separate key-checking hardware that accelerates the process and keeps it secure, enabling real-time EMTE for all critical processes. Apple's research indicates that this technology could all but eliminate the problem of memory safety vulnerabilities. iOS on the iPhone 17 series implements MIE in "the kernel and over 70 userland processes", but Apple is also making this technology available to third-party developers via new Enhanced Security settings in Xcode.