[bign256] Digital signature #68

Job	Run time
build (1.65.0, thumbv7em-none-eabi)	3m 39s
cross (armv7-unknown-linux-gnueabihf, 1.65.0)	4m 17s
build (1.65.0, wasm32-unknown-unknown)	3m 55s
cross (armv7-unknown-linux-gnueabihf, stable)	2m 4s
build (stable, thumbv7em-none-eabi)	21s
cross (aarch64-unknown-linux-gnu, 1.65.0)	4m 16s
build (stable, wasm32-unknown-unknown)	28s
cross (aarch64-unknown-linux-gnu, stable)	3m 29s
cross (powerpc-unknown-linux-gnu, 1.65.0)	3m 52s
doc	1m 21s
cross (powerpc-unknown-linux-gnu, stable)	2m 28s
test (i686-unknown-linux-gnu, 1.65.0, sudo apt update && sudo apt install gcc-multilib)	2m 17s
test (i686-unknown-linux-gnu, stable, sudo apt update && sudo apt install gcc-multilib)	1m 48s
test (x86_64-unknown-linux-gnu, 1.65.0)	1m 59s
test (x86_64-unknown-linux-gnu, stable)	1m 41s
	37m 55s

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