Encrypted 1-bit audio distribution system

An internet protocol (IP) pulse density modulation (PDM) audio transmitter apparatus adapted to transmit an encrypted PDM 1-bit data stream over an Ethernet network, said apparatus comprising:

• (a) an acoustic sensor element;
• (b) a sigma-delta modulator adapted to convert an analog input signal into a pulse density modulated 1-bit data stream at a predetermined audio oversampling rate;
• (c) a processor and memory adapted to compute and produce a first pseudo-random 1-bit data stream at a predetermined encoding rate;
• (d) a first exclusive-or (XOR) logic gate operatively connected to the pulse density modulated 1-bit data stream and the pseudo-random 1-bit data stream in such a manner as to produce an encrypted pulse density modulated 1-bit data stream at the predetermined audio oversampling rate;
• (e) a first first-in first-out (FIFO) memory configured to load the encrypted pulse density modulated 1-bit data stream at said predetermined audio oversampling rate and to unload Ethernet pulse density modulated frame data at a predetermined Ethernet physical layer (PHY) transfer rate;
• and
• (f) an Ethernet interface configured to accept the Ethernet frame data at the predetermined Ethernet PHY transfer rate and to transmit Ethernet data packets on a network.

An internet protocol (IP) speaker apparatus adapted to receive a 1-channel encrypted pulse density modulation (PDM) 1-bit data stream over an Ethernet network, said apparatus comprising:

• (a) an Ethernet interface configured to receive Ethernet data packets on a network;
• (b) a first-in first-out (FIFO) memory configured to load the Ethernet data packets at a predetermined Ethernet physical layer (PHY) transfer rate and to unload an encrypted pulse density modulated 1-bit data stream at a predetermined audio oversampling rate;
• (c) a processor and memory adapted to compute and produce a pseudo-random 1-bit data stream at a predetermined encoding rate;
• (d) an exclusive—or (XOR) logic gate operatively connected to the encrypted pulse density modulated 1-bit data stream and the pseudo-random 1-bit data stream in such a manner as to produce an unencrypted pulse density modulated 1-bit data stream at said predetermined audio oversampling rate;
• (e) a decimator filter adapted to convert the unencrypted pulse density modulated 1-bit data stream into a pulse code modulated N-bit digital data stream at a predetermined audio sampling rate;
• (f) a digital to analog converter adapted to convert the N-bit pulse code modulated digital data stream into an analog output signal a said predetermined audio sampling rate;
• and
• (g) a loudspeaker configured to receive the analog output signal.

An internet protocol (IP) loudspeaker apparatus adapted to receive a multi-channel encrypted pulse density modulation (PDM) 1-bit data stream over an Ethernet network, said apparatus comprising:

• (a) a first-in first-out (FIFO) memory configured to load Ethernet data packets at a predetermined Ethernet physical layer (PHY) transfer rate and to unload a plurality of encrypted pulse density modulated 1-bit data streams at a predetermined audio oversampling rate;
• (c) a processor and memory adapted to compute and produce a plurality of pseudo-random 1-bit data streams at a predetermined encoding rate;
• (d) a plurality of exclusive-or (XOR) logic gates, each of said XOR gates operatively connected to a corresponding one of said plurality of encrypted pulse density modulated 1-bit data streams and a corresponding one of said plurality of pseudo-random 1-bit data streams in such a manner as to produce a corresponding plurality of unencrypted pulse density modulated 1-bit data streams at said predetermined audio oversampling rate;
• (e) a plurality of decimator filters adapted to convert each of said plurality of unencrypted pulse density modulated 1-bit data streams into a corresponding plurality of N-bit pulse code modulated (PCM) digital data streams at a predetermined audio sampling rate;
• (f) a digital audio mixer configured to accept the plurality of N-bit pulse code modulated digital data streams and to produce a combined pulse code modulated N-bit digital data stream multi-channel output;
• (g) a digital to analog converter adapted to convert the combined PCM N-bit digital data stream into an analog output signal at said predetermined audio sampling rate;
• and
• (h) a loudspeaker configured to receive the analog output signal.