All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.
Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.
elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParentResearch by Grayson Martin
Last Updated 7/8/23
Value Added Services (VAS) is the protocol used by NFC capable passes in Apple Wallet. Access to this protocol is heavily restricted on both the device end (a special certificate issued by Apple is required to create these passes) and the reader end (NDA enforced confidentiality). As such, a desire arose to better understand the protocol in order to explore additional use cases and examine its cryptographic integrity. There are gaps in understanding in certain parts of this protocol, however this document contains the minimum necessary understanding to automatically select, read data from, and decrypt a pass.
Importantly, this specification does not enable a malicious actor to read the data from a pass for which they do not have both the reader's private key, and the pass type identifier. Imp
