Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Viaccess is a conditional access system developed by France TÃ©lÃ©com. There are six versions in use today, Viaccess PC2.3, Viaccess PC2.4, Viaccess PC2.5, Viaccess PC2.6, Viaccess PC3.0 and Viaccess PC4.0. Viaccess was developed as the digital version of the EuroCrypt system used with the hybrid MAC system. The first version is sometimes referred to as Viaccess 1, and the latter three, although different, as Viaccess 2. PC2.3 and PC2.4 are known to be ineffective, and many set-top boxes can be ''patched'' to decrypt Viaccess signals without payment, however PC2.5 and PC2.6 are secure, with PC2.5 remaining secure two years after its first commercial deployment. PC2.6 was introduced at the end of 2005. PC3.0 was introduced during mid-2007.