Electromagnetic interference or EMI is any electromagnetic disturbance that interrupts, obstructs, or otherwise degrades or limits the effective performance of electronic or electrical equipment. It can be induced intentionally, as in some forms of electronic warfare, or unintentionally, as a result of spurious emissions and responses, intermodulation[?] products, and the like. It is also known as radio frequencyinterference.
... key, which the DVD Consortium kept secret. In order to gain access to the key, a DVD player manufacturer would have to sign a licence agreement with the DVD ...