Doc crypto #468

Job	Run time
all-features	1m 29s
build (linux)	2m 7s
build (macos)	2m 20s
long-tests	4m 2s
build (windows)	4m 33s
test-bindings-c-cpp-linux	46s
afl-build	4m 52s
audit	5s
clippy	3m 42s
fmt	8s
publish-dry-run	3s
test-bindings-c-cpp-windows (Debug-c, x86_64-pc-windows-msvc)	1m 27s
test-bindings-c-cpp-windows (Debug-c, i686-pc-windows-msvc)	1m 34s
test-bindings-c-cpp-windows (Release-c, x86_64-pc-windows-msvc)	1m 3s
test-bindings-c-cpp-windows (Release-c, i686-pc-windows-msvc)	1m 20s
test-bindings-c-cpp-windows (Debug-cpp, x86_64-pc-windows-msvc)	1m 29s
test-bindings-c-cpp-windows (Debug-cpp, i686-pc-windows-msvc)	1m 27s
test-bindings-c-cpp-windows (Release-cpp, x86_64-pc-windows-msvc)	1m 3s
test-bindings-c-cpp-windows (Release-cpp, i686-pc-windows-msvc)	1m 13s
	34m 43s

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