Using OpenSSH Manually encrypt and decrypt files

# Generating keys and encrypt/decrypt files using OpenSSL
PRIVATE_KEY=private1.pem
PUBLIC_KEY=public1.pem
PLAIN_TEXT=secrets.txt
ENCRY_TEXT=${PLAIN_TEXT}.enc
PLAIN_TEXT1=secrets1.txt
#
# Generate Private and Public Keys
openssl genrsa -out $PRIVATE_KEY 8192
openssl rsa -in $PRIVATE_KEY -outform PEM -pubout -out $PUBLIC_KEY
# Encrypt
openssl rsautl -encrypt -in $PLAIN_TEXT -out $ENCRY_TEXT -pubin -inkey $PUBLIC_KEY
# Decrypt
openssl rsautl -decrypt -in $ENCRY_TEXT -out $PLAIN_TEXT1 -inkey $PRIVATE_KEY
# Verify
diff $PLAIN_TEXT $PLAIN_TEXT1