Default encryption when AESKey not set?

[MLB-BIOMETRIC]

Hello!

I am wondering what is the default encryption when AESKey is not set for ZipOutputStream.

Example code below:

    public static byte[] ZipContent(byte[] value, string password)
    {
        using (var ms = new MemoryStream())
        {
            using (var s = new ZipOutputStream(ms))
            {
                s.Password = password;
                var contentEntry = new ZipEntry("_");
                s.PutNextEntry(contentEntry);
                s.Write(value, 0, value.Length);
            }
            return ms.ToArray();
        }
    }