The invention relates to a multimedia contents processing device, able to receive encrypted multimedia contents, protected by a contents protection system, and to provide said multimedia contents in decrypted form to a user device, comprising means for implementing access control authorizing the provision of said decrypted multimedia contents to said user device, means for executing security services having a first associated level of security and means for executing services having an associated level of security lower than said first level of security. The device according to the invention comprises a hypervisor (30) able to control the execution of at least three groups (G1, G2, G3) of virtual machines, said groups of virtual machines being executed in a strictly separate manner, the first two groups being dedicated to the execution of services of a lower level of security than the first level of security and the third group (G3) of virtual machines able to implement security services of first level of security and to ensure the role of trusted third parties for services of said first and second groups of virtual machines.