Encryption using openssl is one of the quickest way to to encrypt or decrypt secret messages. Here is one I am using as example:

echo "secret msg" | openssl enc -e -aes-256-cbc -pbkdf2 -a

This going to ask for password. It can be skip with:

 --pass pass:password 

The password I used here is "neovoid"

This is the cypher text I got:

 U2FsdGVkX18jPehEW2OSmzlMvgetmG0iKQJVd64F+AY= 

To decrypt it use -d option

 echo "U2FsdGVkX18jPehEW2OSmzlMvgetmG0iKQJVd64F+AY=" | openssl enc -d -aes-256-cbc -pbkdf2 -a 

I hope My secret message is visible now.