In order to generate release key hash you need to follow some easy steps.
1) Download Openssl
2) Make a openssl folder in C drive
3) Extract Zip files into this openssl folder created in C Drive.
4) Copy the File debug.keystore from .android folder in my case (C:\Users\SYSTEM.android) and paste into JDK bin Folder in my case (C:\Program Files\Java\jdk1.6.0_05\bin)
5) Open command prompt and give the path of JDK Bin folder in my case (C:\Program Files\Java\jdk1.7.0_40\bin).
6) Copy the following code and hit enter
keytool -exportcert -alias abcd-keystore D:\Projects\MyAppFolder\keystore.txt | C:\openssl\bin\openssl sha1 - binary | C:\openssl\bin\openssl base64 ex - keytool -exportcert -alias (your sing apk alias name enter here like my sign apk alian name is abcd )-keystore "signed apk generated keystore apth enter here" | "openssl bin folder path enter here" sha1 - binary | "openssl bin folder path enter here" base64
7) Now you need to enter password, Password = (enter your sign keystore password here)
8) you got keystore which are used for release app key hash