Please only post problems once @Saranya - your duplicate is here.
Things to try:
- Add -
v
flags to your SSH command to show what is happening, then paste those logs here in a formatted block - Set up a dummy project in BitBucket, create a throwaway public/private key for it, put in the public key in CircleCI, push an example commit, and then show us the keys that you have set up. Last time I went through this with someone, they had an (obvious) line break in one of their keys.