generate a random secret key for encryption/decryption
openssl rand -hex 32
to encode a string
node index.js -e --key=rand_openssl_key "string to encode"
# outputs encoded-string-hash:
# 8d1683d960adea7d5883ee943ccba5611bea44974193de23002ff617bf4d5856
to decode a string
node index.js -d --key=rand_openssl_key encoded-string-hash
# outputs original string:
# string to encode