Problem Scenario: You want to delete all commit history but keep the code in its current state.
Solution: In order to achieve this, Deleting .git folder may cause problems in your Git repository. Therefore follow below steps through command line to solve the above problem scenario.
Step 1: Checkout to some new branch

git checkout --orphan new_branch

Step 2: Add all the files

git add -A

Step 3: Commit the changes

git commit -am "commit message"

Step 4: Delete the master branch

git branch -D master

Step 5: Rename the current branch to master

git branch -m master

Step 6: Force update your repository

git push -f origin master

Steps to create self signed certificate on Windows:

1. Open visual studio Developer Command Prompt as administrator  
2. Execute below mentioned commands in sequential order. It will create a certificate with SHA.256 algorithm.You can modify parameters as per your requirements.
   Command format:

   makecert –a SHA256 -sv SAMPLE.pvk -n "cn=SAMPLE" SAMPLE.cer -b <start_date> -e <end_date> -r

   pvk2pfx -pvk SAMPLE.pvk -spc SAMPLE.cer -pfx SAMPLE.pfx

   Example:

   makecert –a SHA256 -sv "C:\Sample.pvk" -n "cn=Sample" "C:\Sample.cer" -b "10/22/2018" -e "10/22/2019" -r

   pvk2pfx -pvk "C:\Sample.pvk" -spc "C:\Sample.cer" -pfx "C:\Sample.pfx"

3. Install the pfx file for current machine or current user as per requirements

References:

1. https://docs.microsoft.com/en-us/windows/desktop/SecCrypto/makecert
2. https://docs.microsoft.com/en-us/windows-hardware/drivers/devtest/pvk2pfx

UPDATE: (April 15, 2019)

Use this powershell command to create self signed certificate as MAKECERT command has been depretiated.