The invention relates to a process for hydrodeoxygenation of pyrolysis oil and also to a process for upgrading of pyrolysis oil implementing said HDO process, and also to processing of the aqueous phase resulting from the HDO by steam pre-reforming and then steam reforming. According to one embodiment, a method of mitigating DDoS attacks is provided. Encrypted content is made available to a recipient together with a decryption code, if the identity of the recipient can be confirmed through a validation procedure and if the release conditions are met.