What is the correct shasum of InstallESD.DMG for OS X 10.10 Yosemite? apples-mbp:~ apple$ shasum /Applications/Install\ OS\ X\ Yosemite.app/Contents/SharedSupport/InstallESD.dmg
142a3186e05932b60e2100452777eab3346913da  /Applications/Install OS X Yosemite.app/Contents/SharedSupport/InstallESD.dmg


This the result i got when I run shasum, I am getting a checksum error on installation file.
The correct sha1 of InstallESD.DMG for OS X 10.10.0 Yosemite is eebf02a20ac27665a966957eec6f5e6fe3228a19.

There's no way to correct corrupted downloads, so you have to download it again.