1. A method in a communication system for authentication of at least one of a sender device and a receiver device in said communication system, said method comprising:
creating, by said sender device, an identification of said sender device;
creating, by said receiver device, an identification of said receiver device;
sending, by said sender device, a request pertaining to establishing a relation between said sender device and said receiver device to said receiver device;
sending, by said receiver device, at least an identification of a second master device to said sender device;
sending, by said sender device, said identification of said second master device to a first master device;
sending, from said first master device, a request pertaining to communication conditions needed by said sender device for said sender device to establish communication with said receiver device to said second master device;
sending, from said second master device, said communication conditions to said first master device; and
in a case said sender device fulfills said communication conditions,
providing, by said sender device, a first access key to said first master device; and
providing, by said receiver device, a second access key to said second master device.
2. The method according to claim 1, wherein said request pertaining to establishing said relation between said sender device and a receiver device to said receiver device comprises at least an identification of a first group of devices, said method further comprising:
receiving, by said receiver device, said request;
sending, by said receiver device, at least an identification of a second group of devices to said sender device; and
receiving, by said sender device, said identification of a second group;
in a case there exists at least one third device, which is a device being one of the devices in both said first group and said second group of devices,
sending, by said sender device, a request pertaining to a reference from said at least one third device regarding said receiver device;
receiving, by said receiver device, said reference request and sending, by said receiver device, said request to said at least one third device;
receiving, by said receiver device, said reference and sending, by said receiver device, said reference to said sender device;
receiving, by said sender device, said reference; in response thereto;
creating, by said sender device a first public encryption key for establishing communication from said sender device to said receiver device;
encrypting, by said sender device, said reference using said first public encryption key;
encrypting, by said sender device, said first public encryption key using an additional public encryption key;
sending, by said sender device, said encrypted reference and said encrypted first public encryption key to said receiver device;
sending, by said receiver device, said encrypted first public encryption key to said at least one third device;
decrypting, by said at least one third device, said encrypted first public encryption key;
sending, by said at least one third device, said decrypted first public encryption key to said receiver device;
decrypting, by said receiver device, said encrypted reference; and
validating, by said receiver device, said decrypted reference.
3. The method according to claim 2, wherein the communication system further comprises a fourth device and a fifth device, and wherein said sender device is associated with said fourth device, said receiver device is associated with said fifth device and said fourth device is associated with said fifth device; and wherein in a case there does not exist at least one third device which is a device being one of the devices in both said first group and said second group of devices, said method further comprising:
sending, by said sender device, a request pertaining to a reference from said fifth device regarding said receiver device, wherein said request is sent to said receiver device;
forwarding, by said receiver device, said request to said fifth device;
sending, by said fifth device, said reference to said receiver device;
forwarding, by said receiver device, said reference to said sender device;
sending, by said sender device, said reference to said fourth device;
validating, by said fourth device, said reference and sending, by said fourth device, said validated reference to said sender device;
creating, by said sender device a first public encryption key for establishing communication from said sender device to said receiver device;
encrypting, by said sender device, said reference using said first public encryption key;
encrypting, by said sender device, said first public encryption key using an additional public encryption key;
sending, by said sender device, said encrypted reference and said encrypted first public encryption key to said receiver device;
sending, by said receiver device, said encrypted first public encryption key to said fourth device via said fifth device;
decrypting, by said fourth device, said encrypted first public encryption key;
sending, by said fourth device, said decrypted first public encryption key to said receiver device via said fifth device;
decrypting, by said receiver device, said encrypted reference; and
validating, by said receiver device, said decrypted reference.
4. A method performed by a sender device for enabling authentication, said method comprising:
providing a sender device;
creatin an identification of said sender device;
sending a request pertaining to establish a relation between said sender device and a receiver device to said receiver device, wherein said request comprises at least an identification of a first group of devices;
receiving at least an identification of a second group of device from said receiver device; and
in a case there exists at least one common third device in said first group and said second group of devices,
sending a request pertaining to a reference from said at least third device regarding said receiver device;
receiving said reference from said receiver device;
creating a first public encryption key for establishing communication from said sender device to said receiver device;
encrypting said reference using said first public encryption key;
encrypting said first public encryption key using an additional public encryption key; and
sending said encrypted reference and said encrypted first public encryption key to said receiver device; and
wherein said sender device is associated with a fourth device, said receiver device is associated with a fifth device and said fourth device is associated with said fifth device; and wherein in a case there does not exist at least one common third device in said first group and said second group of devices, said method further comprising:
sending a request pertaining to a reference from said fourth device regarding said receiver device; wherein said requesting is forwarded from said fourth device to said fifth device;
receiving said reference from said fourth device;
creating a first public encryption key for establishing communication from said sender device to said receiver device;
encrypting said reference using said first public encryption key;
encrypting said first public encryption key using an additional public encryption key; and
sending said encrypted reference and said encrypted first public encryption key to said receiver device.
5. A method performed by a receiver device for enabling authentication, said method comprising:
providing a receiver device;
creating an identification of said receiver device;
receiving a request pertaining to establishing a relation between said receiver device and a sender device from said sender device, wherein said request comprises at least an identification of a first group of devices;
sending at least an identification of a second group of devices to said sender device; and
in a case there exists at least one common third device in said first group and said second group of devices,
sending a request, from said receiver device, pertaining to a reference from said at least third device regarding said receiver device;
sending said reference to said sender device;
receiving, by said receiver device, an encrypted reference and an encrypted first public encryption key;
sending said encrypted first public encryption key to said at least one third device;
receiving a decrypted first public encryption key;
decrypting said encrypted reference; and
validating said decrypted reference, and
wherein said sender device is associated with a fourth device, said receiver device is associated with a fifth device and said fourth device is associated with said fifth device; and wherein in a case there does not exist at least one common third device in said first group and said second group of devices, said method further comprising:
sending a request pertaining to a reference from said fifth device regarding said receiver device; wherein said requesting is forwarded from said fourth device to said fifth device;
sending said reference to said fifth device;
receiving an encrypted reference and an encrypted first public encryption key;
sending said encrypted first public encryption key to said fourth device via said fifth device;
receiving said decrypted first public encryption key;
decrypting said encrypted reference; and
validating said decrypted reference.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A gas circulation fan for an excimer laser apparatus circulating laser gas in a chamber by fan rotation, comprising:
a rotary shaft on which said fan is attached;
a controllable magnetic bearing supporting, in a non-contact manner, said rotary shaft;
a control circuit controlling said controllable magnetic bearing;
a motor for rotating said rotary shaft; and
a compensator provided between said controllable magnetic bearing and said control circuit, compensating for variation in characteristic resulting from individual difference of the controllable magnetic bearing.
2. The gas circulation fan for an excimer laser apparatus according to claim 1, wherein
said compensator includes
a detector for detecting a sensor signal of said controllable magnetic bearing,
an offset adjusting circuit correcting positional deviation of said rotary shaft from the center, based on the sensor signal detected by said detector,
a feedback gain adjusting circuit adjusting gain of the detection output of said detector, and
a filter circuit for reducing proper oscillation of said rotary shaft.
3. The gas circulation fan for an excimer laser apparatus according to claim 1, further comprising:
a housing accommodating said controllable magnetic bearing; wherein
said compensator is provided in said housing.
4. A gas circulation fan for an excimer laser apparatus circulating laser gas in a chamber by fan rotation, comprising:
a rotary shaft on which the fan is attached;
a controllable magnetic bearing supporting, in a non-contact manner, said rotary shaft;
a control circuit controlling said controllable magnetic bearing;
a motor for rotating said rotary shaft; and
an adjusting member adjusting natural frequency of a rotary body rotating integrally with said rotary shaft.
5. The gas circulation fan for an excimer laser apparatus according to claim 4, wherein
said adjusting member includes a weight detachably attached on said rotary shaft.
6. The gas circulation fan for an excimer laser apparatus according to claim 4, wherein
said adjusting member includes a female screw portion formed along an axial direction from the side of one end surface of said rotary shaft, and
a natural frequency adjusting member having a male screw portion formed on an outer circumferential surface and moved forwardbackward engage with said female screw portion.
7. A gas circulation fan for an excimer laser apparatus circulating laser gas in a chamber by fan rotation, comprising:
a rotary shaft on which said fan is attached;
a controllable magnetic bearing supporting, in a non-contact manner, said rotary shaft;
a control circuit controlling said controllable magnetic bearing; and
a motor for rotating said rotary shaft; wherein
said control circuit includes
a bandpass filter for removing natural oscillation frequency of said rotary shaft, and
a frequency setting circuit for setting set frequency of the bandpass filter to natural frequency of said rotary shaft.