Editing /dev/random (section)

==macOS, iOS and other Apple OSes==
All Apple OSes have moved to Fortuna since at least December 2019, possibly earlier.<ref>{{cite web|url=https://support.apple.com/en-ie/guide/security/seca0c73a75b/web|title=Apple Platform Security|publisher=[[Apple Inc.]]}}</ref> It is based on [[SHA-256]].  Multiple entropy sources such as the secure enclave RNG, boot phase timing jitter, hardware interrupt (timing assumed) are used.  RDSEED/RDRAND is used on Intel-based Macs that support it.  Seed (entropy) data is also stored for subsequent reboots.

Prior to the change, [[macOS]] and [[iOS]] used 160-bit [[Yarrow algorithm|Yarrow]] based on [[SHA-1]].<ref>{{cite web|url=https://opensource.apple.com/source/xnu/xnu-1456.1.26/bsd/dev/random/|title=xnu-1456.1.26/bsd/dev/random|publisher=[[Apple Inc.]]|access-date=18 October 2016}}</ref>

There is no difference between {{nowrap|{{mono|/dev/random}}}} and {{nowrap|{{mono|/dev/urandom}}}}; both behave identically.<ref>{{man|4|random|Darwin}}</ref><ref>{{cite web|url=https://www.apple.com/ipad/business/docs/iOS_Security_Oct12.pdf|title=iOS Security|date=October 2012|publisher=[[Apple Inc.]]|access-date=May 27, 2015|archive-url=https://web.archive.org/web/20140405001141/https://www.apple.com/ipad/business/docs/iOS_Security_Oct12.pdf|archive-date=April 5, 2014|url-status=dead}}</ref>