Rails.version => "5.2.1"
RUBY_VERSION => "2.5.1"
JSON Web Token (JWT)がデフォで使えるので一番楽そう
encode
data = 'hogehoge'
token = JWT.encode(data, Rails.application.credentials.config[:secret_key_base])
decode
data, header = JWT.decode(token, Rails.application.credentials.config[:secret_key_base])