checksums

checksums is used at run time in 4 crates.

Number of dependers	checksums version	Downloads/month
2	0.9.1	1.5K
1	0.7.1	23
1	0.5.5	41

Depender			checksums version
		csum		=0.9.1
		cramino		^0.9.1
		tmpshare		^0.5.5
		tarsum		^0.7.0