Just to convince you, I paste everything here, anyway, my user name is not my name.
rocks-MacBook-Pro:Downloads rock$ particle keys server
Found DFU device 2b04:d00a
spawning dfu-util -d 2b04:d00a -a 1 -i 0 -s 3298 -D /usr/local/lib/node_modules/particle-cli/keys/ec.pub.der
dfu-util 0.9
Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2016 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/
dfu-util: Invalid DFU suffix signature
dfu-util: A valid DFU suffix will be required in a future dfu-util release!!!
Opening DFU capable USB device...
ID 2b04:d00a
Run-time device DFU version 011a
Claiming USB DFU Interface...
Setting Alternate Setting #1 ...
Determining device status: state = dfuIDLE, status = 0
dfuIDLE, continuing
DFU mode device DFU version 011a
Device returned transfer size 4096
DfuSe interface name: "DCT Flash "
Downloading to address = 0x00000ce2, size = 320
Download [=========================] 100% 320 bytes
Download done.
File downloaded successfully
Okay! New keys in place, your device will not restart.
rocks-MacBook-Pro:Downloads rock$ particle keys doctor 22002f001951343334363036
Found DFU device 2b04:d00a
Found DFU device 2b04:d00a
New Key Created!
Found DFU device 2b04:d00a
Found DFU device 2b04:d00a
Saved!
spawning dfu-util -d 2b04:d00a -a 1 -i 0 -s 3106:leave -D 22002f001951343334363036_ec_new.der
dfu-util 0.9
Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2016 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/
dfu-util: Invalid DFU suffix signature
dfu-util: A valid DFU suffix will be required in a future dfu-util release!!!
Opening DFU capable USB device...
ID 2b04:d00a
Run-time device DFU version 011a
Claiming USB DFU Interface...
Setting Alternate Setting #1 ...
Determining device status: state = dfuIDLE, status = 0
dfuIDLE, continuing
DFU mode device DFU version 011a
Device returned transfer size 4096
DfuSe interface name: "DCT Flash "
Downloading to address = 0x00000c22, size = 121
Download [=========================] 100% 121 bytes
Download done.
File downloaded successfully
Saved!
attempting to add a new public key for device 22002f001951343334363036
Error sending public key to server: Permission Denied
Make sure your device is in DFU mode (blinking yellow), and that your computer is online.
Error - undefined