HID Readers BLE DoS Attack And DEF CON Hack Examined
While mobile credential usage is gaining, mega access control provider HID has acknowledged a DEF CON 2021 hack and a vulnerability with BLE for multiple reader lines, including HID iClass SE and HID Signo (see IPVM test results).
Inside this note, we examine how the hack works, share detailed feedback from HID on the vulnerability and examine the problems with HID's solution to this.
DEF *** '** (****) *************
* ***** ** *********** ******* * Bluetooth ***-****** ************* ** *** *** 29 **** ****** *** ******-********** ******* and *********** ***** **** **, ********** them **** ******* *** ****** ***********.
** *** ***** *****, **** **** the *** *** (****** ** *******) attack ** ~** *** ******* **** BLE ******* ** ******* ****** ** and ***** ******:
** ********,*** ****** **** ********, ********** *** ******-**-******* ****** **** 'off-the-shelf *******' *** **** ****** ************ it '******** *** ****** **** ***** able ** **** ********** ***********' ****** the *** ******:
How *** ************* ***** - $** *** ***
*** *********** ******** *** *** ****** using ******* ***** ** ************ ********* BLE ******, **** *** **** ********** attacks ***** ** ***$** **************** *** *** ******-********* **** **** flood *** *** *** ****** **** multiple *** ***** ******** ** *******.
*** *********** ************ *** ****** ***** battery-powered ******* **** *** ** ******** hidden ** ****, ******, ** ******* even **** ******* **.
*** ***'* ****, *** ** **** both ** *** ****** *** *** configuration ******* *** ****** ******* ***. The ****** ************ **** ******* *** repeatedly ********** ** ******* ** ****** the ****** *** ** * ********* bad ****** *** **** *** *** same ******, *********** ******* *** ****** from ************* **** *** *********** (***** or *******) *** ** ************* **** the ********* **** ****** **** ***** regardless ** ******* ** **** ** used.
Readers ******* **** ***
*** ********* ********* *** *** ******** floods *** *********** **** **** ****** what *** ****** *** *****, *********** forcing ** ** **** **. *** reader **** ******* ********** ** ***** credentials.
*** *** *** *********** ********* ****, explaining *** *** ******** *** ****** from ****** **** *********:
- ****** * *** ******, ** **-***** is ******** ** *** ******, *********** becoming '**** *******' **** ****** **** other ***********.
- ** *********** ********** ** ******* **, as ** **.** ***/*** *** *** is *******.
- ************, *** '****** ** *** ********** media' ****** *** ****** *** ****** be **********/******** *** ******** ** ******* or ***** *** *** ******.
HID ******** *** *** ***** ** *******
*** ********* ** **** *** ****** renders ***** *********** ********:
** ** ********** ******** *** ** attacker ** ***** *** ****** **** enough ********* *******, **** *********, **** that *** ****** ** ****** ** read *** ***** *********** ********** ***** or ******* ****** ******* *** *** duration ** *** ******.
*******, **** ********* ************** ********* ***** ********* ***** **** ************ ****** * BLE *** ******:
[*** *******] ***********-**** ****** ******** ** generally **** *********** ** ** ************ during * *********-***** *** ******.
What *** **********
** **** **** *** ****, *** recommends ******* *** *** *** ***** in *** *******:
*** *** ********* ****** ********, ********* HID *****, **** ****Bluetooth *** ** ***********, ***** ********** *** **** ** * *********-***** *** ******. Based on HID analysis, we ******* **** ** *** **** ********* ********** for customers who have concerns about Bluetooth-based DoS attacks on readers. [Emphasis Added]
******* ***/********* *** *** ** **** via ***'* ************* ***, *** **** reader **** ** ******** ************, ** BLE ** ****** ** ******* *** no ******* ********** *********** ******** ** multiple ******* ** ****.
Problems **** ********* ***
*******, ******* *** *** *** ****** in *********** ********* *** ****** ********** problems. ************, ********* *** *********** ********** Apple ******** **** ***** *** ******.
*** ****** *** ***** ** **** in ***-**** ****, *** ***** ** reduces *** *** ****** ** ****:
- *** ****** *** ****** **** ***** to ~** ** (~* ******) **** ~100 * (~*** ****).
- **** ***-******* ******* *** ********* *** Readers ** *** ** ********.
** ********* *****, *** ****** '******* activation' **** ***** & ** ** not ********* **** *** ********, *** unless ****** ********** **** ******** (********), iOS *** ****** ******** ***** *** are *** *** ********* ***** ************** ******* **** ****.
** ********, ***'* ****** ************* *******, HID ****** *******, **** *** **** Apple *******, *** ******* ** *** means *********** *** ** ****** *** iPhones ** ********* ********.
Signo ****** ***** ********
*** **** **** ************* ***** ******* a ******** ********* **** ** ***** own, *** *** ******* **** ******** to *** *** ****** ******* *** instead ** ************* *****:
** *** **********, *** ******* ** organization **** **** *** ******** * potential **** ** *** ******* *** Bluetooth **** **** *** ****** *** inherent ******** *********** ** ************* *****. So, *** ******* ********** ** ** offer **** ****** ************* ************* **** a **** **** **** ******** * real-time ********** *********** ****** (*** ****** Manager).
Unclear ** ******** ****** ** *** ******* ****** ** *******
*** *** *** ******* ******* *** 'permanent' *** ***** **** *** * firmware ****** ** ******* ********* *** potential ******** ******* **** *** *****:
***** *** ** ************* **** ** are ******** ** *********** ** **** time.
********* ** *** ********* **********, ******** mitigation ** * *** **** ********* is *********** ** ******* **** ********* communication *******. ****, ********* *** ******** the **** ** ** ******** ****** deactivate ********* ************* ** ***** *******.
Impact ** ***** ****** ***********
***** *** *********** **** ******** **** vulnerability **** ***, ** ** ******** that ***** ******* ***** *** *** susceptible ** *** **** **** ** attack.
******, *** ** ******** **** ** mobile ******, ***** ** ***** ** option *** ******** ********* ********* *** ones ****** ** ********* ****** ******* ********.
*******, ******* ***** ** ***** ***** customers. ** *** *** **** ********** to ** **** ***** **** ** no ********** **** ** ***, * imagine **** **** ** *******. * would ** ** ****. *******, ** they *** ******* ** ****** *** a **** *** ********** ***** *** the *****, *** *** *** ******* to ***** **, **** ***** ****** be ** ******* ** ***.
** **** **** ***** ****** ***** SEOS **** ******* *** *****. *** sure *** **** *** **** *** looking ** ** * *** ******. None ** *** ********* **** ****** to *** *********** ** ***********. *** it ** ** *********** *******...
*** *******, *** *****-****** ** ******* does *** ****** ******* **** ******-**-*******.
***** **** ** ********** **** * would **** * "****" ** *** product **** *****'* ******* *** **** type ** *** ******, ******* **** a "*************" ** * ******* ***** upon *** *********** ********** ** **** *****.
************, ***** **** ** **** ********** something **** ***** *** ***** ******* operations ** ** ********, * ***'* see *** ****** ******** ************* ********* here. **** ***'* ******* *** ****** to **** ************** ******* ** **** signals ** *** **** ***. **'* not ******** *** ****** ** ** SEOS ********** **** ** *** ********, or ******** *** ****** **** ****** of * ****** ********** ** ** sniffed ** ****** **** ** *** reader.
***** ** ****** ******* ***** ** call **** * "********* *************", * don't *** ******** **** **** ***** compel ** ** ********* ** ** clients **** **** ******* ********* ********** to ******** ****. *** ***** **** happens -- ** ********* **** -- is ******* **** * ****** *** stops ** **** *******.
****** ********, ** *** ****** **** me *** *'* ***** ****? ************ am ******* ** *****'* ********* *'* missing ** ** **** ** ****, because ** ***, **'* * *** bag ** ******* ** **'* **** presented ** ***.
* #*, *** ***** ** *** reader(s) **** *** ****** (****** * person, ** * ******-********** ******* ******) need ** **?
**** *** ****** ** ******* **** the ****, ** **** *** ******* device ** ******* *** ********/*****, ** the ***** ******?
******* **** ***** ***** ** * problem ** ******* ********** ***** ** at *:** ** **** **** *** and **** *** ** * ********'* readers, *** ********** *** ******* **** stop *** *** ** *******.
*** ******* ********* **** ** **** able ** ******* ******* ********* ** turnstiles **** ************* ***** **** **** a ******* *** ******* ************* ** special *********. *** **** *** ********* using *** $** ****** **** **** a "**** *******", ***** **** ********* have *** ***** ***********. ***** ** is ***, **** ***** ** ****** variable *** ***************-*********.
*** ***** *** ** ********* **** more ********* ******** *** ********* ************.
**** * ***** **** * "****"... calling **** * "*************" ** * stretch
*'** ******* *** ***** ** "*** ******* *** *** ****** *** DEF *** **** ********" *** ******* the **** **** *****. * ***** that ** *** **** *******, ****** way ** *********** *** *****.
*******, **** (****)**********:
******** ** ** *********** ******, ****** security **********, ******** ********, ** ************** that ***** ** ********* ** ********* by * ****** ******.
***** ****'* **********, **** ** ***. They **** **** * ******* ****** but *** ******* ** *****.
*********, *** *** ****** *** **** of ** ***** **** ** *** to ****.
** *******, * ****'* ******** *********** the *** *** ******* *** *******, or *** ****** ***** ** *** word "*************." * ******* ****'* ****** how ** **** ***, *** *'** admittedly *** **** *** ***** *********** similar ****** ** *** **** ** I ********** *** *************. * ******** thought **** ******* *** ********* ******* it **** ******* ******* ** *** actual **** *** *** ********** *****.
** *********** ***** *** **** **** to ******* **** * ** *** personally ********* ***** **** (***** ** what ** **** ***) ******** ** other "***************" ** **** ******** ********, and ** *** ** * *** missing ********* **** ***** ***** **** to ** **** *******.
*** *** ****** *** ******* ********. Impact ** **** **** *********-*********, *** your ***-***** *** *** ** ********* impacted.
*********'* *** *****:
** *******, * ************* ** ******* as * ******** ** *** ************* logic (*.*., ****) ***** ** ******** and ******** ********** ****, **** *********, results ** * ******** ****** ** confidentiality, *********, ** ************.
**** **** **** ** ** ******** to ****** *****, ***** ** **** ** *** goal ** *********** ********.
**** ******'* **** ******** ** *** word "*************" ** * ******** ***** is **** *** ***** ** ********** ways ** ****** *** *************** ******* (such ** ******** ********** **** ** sniffing ***********, ** *** *********).
** *** ****** **** ** ** technical ***** **, * ******* *** could *** **** ******* *** ********** to ****-******* ******* **** **** ********. The ****** **** *** ***'* **** heavy ************* **** **** ************* ** because **** **** ** ****** ** not ** **** ****** ***** (****** you ****** ** **** ** ** area **** *** ****** **** ******* usage). ********, ** **** ******** *** should ******** ******* * ********* ******* attack ** ** **** ****** ***** before ********** *** ******.
** ********** *** ** ****** ** service. ** ******** *** ************* ** the ****** **** *** ***** * security ***** **** **** ***** ** a ******* ****** ** *** ***** place?
* ***** *****, *******, *** **** is ***. **** ****** ******** *** be ******. **** ****** *** ********** but **** *** ****** ***** ***** this. *** ****** ** **** ****** to ** ******** ** ******.
** **** ******** ********, ** *** are *** ******* **, ** ** not * *** **** ** *******. Less ******* **** ** ****** ******.
*** **** *** ****** ****** *** so ****** **** ****** **** ***** readers ********** ** * ****** ** service. **** *** *** ****
***
* *** ********* ** ********** ** that "*******" ** * **** **** is ***** ****** ****** *** ****** understood. *********** "*******" ********* ****** ** transmission ** * ******** ********* ****** that ******** * ********* ****** **** that ** ****** ** "*****" ** "understood". **** ** **** ** ***** referred ** **** **** ***** ***** to "*** *******" ** "**** ***** jamming". *** *** ***** ****** ** this ** "******* ************".
**** ******** **** ** ******* ** illegal ***** *** *********** *** ***-******** applications ** *** ** *** **** other ***** ** *** *****.
*** *** ** ******** **** ** not ******* ******* ***** ** ** attempt **** ** ******* *** ***** radio ************. *** ******* ** ******** are ********* ** ********, **** ** they *** *** ********* ** ********.
** *** ****** ** ********, **** is ******** ** **** ** **** again. ****** *****? **-**********? **** ** just ***** ******* ** **'* *** again ***** * ****** ** ****?
** **'* **** **** *** *** count *** * ******** *** ** wait *** ***** ******* **** ** come *** *** ****** **, ****** they **** *********** ******* ** ******* into *** ********. * ***, ********. This ** * *******, *** ** larger ********** ***** ***** **** ** a **** ** ** ****** ******* to *** **. **** *** ***** could *********** '*****' ** **** *** group *** ****'** *** ****** ****** to *** ******** ******* ****** ******.
********* * ** ***** **** ***. It's ******** ** ** ******* ** some ***, *** ******* *** ****** been *********** ***********.
*** *** ******* ** **** **** is * ****** ** ******* ****. Nothing ********* ** ************ ** *** presentation ***** ********** *** ********* ********** information ** ******** ***** ************ ******.
*** ****** ** *** ******* ** directly ******* ** *** ***-***** **** on ***** *******. ** **** **********, this ***** ** **** "************". *******, it ** ********* ** ******** **** the ***** ** * ********** ********* may *** ** ** ****** ** "get ******". **** *** ******* ** intending ** ******* ** ******* ****** operation. ******** ** *** ******* ********** of "***** **** ** *** ****". Bad *** *****'* *** **, *** then...neither ** ***.
** **** ***** **** *** *** matter. *******, ** *** **** ** turnstiles, ******** ********** *******, ** *** rooms ** ******* ******* ** ** emergency ********, ** *** ******.
******* ******** ******* **** ****** ** the ***** ******* **** ******** ********* or ********* * ****, *** ********** override **** ********* **** ** ****, but ***** *** *** ***** ********** solutions **** *** ******* **********.
** **** ****, "****" ** **** than * *** ** * *******, in ** *******.
* ******** ** ********** ****, *************, gains *** ****** ********* **** ********* would *** ** **** ** *** or ******.
**** ***** *** ******** ******* ******* of ***** * ***-***** ****, *** only ***** *** ****** ********, ***** requires **** (**** **********) ****** ****** in *** *** ******.
**** ** ********* ********* *********, ** a ***** ***** **** ********* ********* into * *******.
*** ******* *** ** ****, *********... but **** *** ****** ********* ***** it ******** *** ******** ******** ** a ********** ******.
**** ******* *** ****, *** ** described **** ** * ****** ******** attack.
*** ***** *** **** **** * jamming ****** *** ** **** ********* premises *** ****** ***-***** ** ***** offices?
*** ***** *** **** **** ******** airtags, ******** ******* ******* **** *****?
******** *** - ************ ** ******** - *** - ******* ******** - yes.
*** **** ***** ******* ** ******* a ***-************ *** ****** **** **** are $**-*** -- **** * ******** Soldera. * ***'* **** **** (***) SI's **** **** **** ** ********* to **** *** ********* ******/*.
**** ********* ******* **** ** ******* and *** **** **** ** ** and ********** ***** **** *** ** disable *** -- *** ******* *** can't ******* **** *** ****** *******, you **** **** ** **** **** off *** ****, **** **** *** of *** **** ** ******, ****** them *** ***** **** **** *** reinstall.... *** **** ** ****** *** this *****, *** ****** *** ?
**** **** **** *** ***** ********, because ** **** **** * *** of **** ****** *** ******* ********* not ******* ** *** ** ******* a *** ***..
*** ***** *** **** **** * jamming ****** *** ** **** ********* premises *** ****** ***-***** ** ***** offices?
* ***** **** *** ****** *** of *** *** ** *** ******. 200-300ft ****** **** * **** **** scenario ***** **** ***** * *****-*********** antenna ***** ** *** ********.
*** *.* ** *** **** **** can ****** **** *** *****, *** surprising.
******* *** ******* ******* ******** ********** from ********** ** **** ***** *** walk ****** *** ********. ** **** give *** ** **** ** *** range ** *** ****** ***** **** your ****** **** *******... *** *** whip ******* **** ** **** ** the ****** ** *** ****** *** board *****.
*** ***** **** **** *********** ** understand *** ***** ** *** **** used ** ***. **** ** * long ***** ******* ***** *** *********** board **** ** *** *** ******, nothing *** ******* :
** **** **** **** ****** **** could ***** **** **** ***** **** standard ****. **********, * **** *** tried **** *****, *** * ********** can **** ****** *** ******** *** see *** ****** ** ***** ****** and **** *** ******** **** **** from ** *****'* **** **** *******.
*** *** ** *************** ******** ********** over ***** ** **** * *** idea, ******* ** ***** ** **** with ** *** *** ****** ** better ******* *** * **** ** go ****** *** ******* *** ** the ******.
**** ****, ***.
** **** **** **** ****** **** could ***** **** **** ***** **** standard ****.
******* * ************ **** ** ********* LOS, *** **** *** **** *** with ****** ***.
****’* ** **** - * ***’* have * ***** *** * ** have ** ******, ********** *** **** chip. * *** *** *** *** - **** ** **** * ***:
*** -** *** *** ******* ******* I *** **** *** **** ******. It ***** ******* ***** */* ** the ****.
****, ****** ** ******* ******* *** all ***** ******** *** ****** **** requests.
*’* *** **** ******* *** ** close ***** ****’* ***** ******.
***** **** *** ****** *** ******* it *** -- *** *** ****** the ***** **** *** *.* ** BLE *.* ***** ** **** ** required ** ******* *** ****** ***** mentioned. **** *** ***** **** *** Nordic ***** *** *** ****** **** Nordic ***** ******* *** *.* *** BLE *.* **** *** ******** ***** support ****** ** ***** ***** ******. If *** *** **** *** ***** and *** ****** *** *** *.* you **** *** *** ******* ***** above.
** *** *** **** *** ***** and *** ****** *** *** *.* you **** *** *** ******* ***** above.
* **** ****** ***- ** **** ********* *.* - is **** **** ******?
********** ** *** ***** ***** ****. Newer ******** ** *** *** ******** can ******* ******** *****, *** **'* important ** ********* **** *** ************ in ***** *** ******* ** ******* to *** ******** ************* ******. ***** is * *** **** ********* ****** about **** ****:****** ** ******: ********* **** *****
*******, **** ***** **** **** ******* have ** *** **** **** *** physical ********** ** ******* **** *** protocol, *** ** ********** ** ******** take ********* ** ** ** ****.
** ****** ****** *** ** ***** chip **** ** ********** ****** ** handle *** *** ********, *** ***'* get *** ******** *****. **** ******* having *** *** **** ** **** not ******. *** *********** ******* ** the **** **** *** ** ** compiled **** *** *********** ******* ** the ******** ********* ****** ***********. ** older ********* *** ****, ** ** those *** ******** ****'* ************ ***** advantage **, **** *** ***** ***'* get *** ******** *****.
"****" ** ***** * *** ** stretching ****. ********* * *** ******, but * ******** *** ** **** a *** ******.
***** **** **** *** ******** **** we **** ****.
*******, ** **** ****, ** ************ third ***** ** **** ** ****** the ********** ******** ** * ******* in ****** ** *** *** ********. In ** *** **********, **** ** the ************ ******** ********* ***** ***** that **** ** * "****".
********* ** **** ***-**** ** *** indeed ** **** *** ******, *** not ********* *** *** ** ***** about.
*** ******, ***** ****** ** ****** certain ***** ** ** ********** ****** would ***** **** ******* ************.
*** **** ****** ***** **** ** for ***-***** ** ********** *** ********* limits ** **** ***** ******** ************** will *** **** *** **, *** how ** **** ******* ** ********* scenarios. **** **** *** ******** ** build *** *** **** ** ***** security ***** ** **********.
******* ***** ****** ******* ***** ******* in ***-********* **********? *********** *** ***'* phone ****** ** ******** *** ****** them ** **** ** ********* ***'* working ** ********.
**** ** **** **** ******** ********* always **** ****** ** ********* ******** areas? **** **** * ***** ** override *** ****** ******* ******* *** efficiently ** *** ********* ******** *** it.
******* **** ** * "*** ** falling" *********. ** ** ****** ****** "Some ** ***** ******** *** *** work *** *** *** ****** **** to. **** ***********."
***** *****!
* ** *** ** *** ******* researchers *** **-********** ** *** *****. There *** * *** ****** ** this ******* **** *** ************ **** the ********* ******* **** * ******* I ***** *******.
*. * ******'* ******** *** ****** as * "*****". *** ****** ** not ***** "***********" ** *** *** that *** **** ***** *******. *** reader ** ********* ************ **** ** it. ** **** ****, *** *********** tells *** ****** ** ***** ********** operation *** * *******. ** ****** sure **** *** *********** ** **** again ****** * *******, ** ** ensured **** *** ***** ***** *******, and *** ****** ******* ********* ************.
*. *** **** ********** ****** *** based ** *** $** ******** ******, as *** **** ** ** *** required.
*. **** ***'* ***** "******* ********** to *** ******" ** "********** * bad ****** ****". *** ******** **** are ***** ***** *** ***** ********* as ******** ** *** ******.
*. *** ****** *** *********** ****** is **** *********** ** *** ****** is ******* *** ******* ***** **** only ******** ********** ********* ** *** RFID ******* ** *** ******. *** parts ** *** ****** ********** ************, and ********* **** *** ****** ******** and ** *** ***** *** **** code. **** ********* ********* ******* ** RFID **** *** ********.
*. ******* **** *** ******** *** still ** ************ **** *** **** via ****.
****** *** *** ******** *****!
**: '*. **** ***'* ***** "******* ********** to *** ******" ** "********** * bad ****** ****". *** ******** **** are ***** ***** *** ***** ********* as ******** ** *** ******.'
**** **** **** **** * ***** good ********** **** ** ****? *** HID ****** *********** * ***** '***' or ****** *** **** ** ***** in ***** *** * ********** ** be ********. ** **** *** ********?
**** **** **** **** * ***** good ********** **** ** ****? *** HID ****** *********** * ***** '***' or ****** *** **** ** ***** in ***** *** * ********** ** be ********. ** **** *** ********?
*** *** *** ******* ** ** with ****** *********** ** **** ** any ****. *** *********** **** *** need ** ** ***** ****** ***********.
*** ****** **** ** *** **** any ****** **, ********** **, ** Signo ****** **** *** *** *******, regardless ** ******* *** *** ** has *** **** *********, ********* ** a **********, ** ********** **** *** MOB ** ***** ****.
* ******'* ******** *** ****** ** a "*****".
****, * **** *****. ** **’* really * *******.
****** * *** ** *****.
** **** ***** ***** *** ****** the ****** ** ******* ** ******** the ****** *** ****** *** ** line ** ****, *** ****** * soffit ** ***** ************* *********, ***** two *********** *********:
*. ****** **** ********* *
*. *** ** **** ***** ****** directional *** ********-**** ********-****** ********* ********
** ***** *****, *** ***** ********* mitigating ********** ********* ********* ** *** reader **** ***** ** ***** ***** the ********* ** ***** *** ********?
****, *** **** ** ****** **** ? :)
****, * **** *****. ** **’* really * *******.
**** ** ** *****, * ****'* picking ** *** *** ****** ****. I *** **** ********** *** ********* of **** *** *********. *** ****** "floods" ** *** **** *** *** is ******* **** ******* * ********* where *** ****** ** ********* ** so ********* **** ** ********** *** infrastructure. **** ** ******* ** **** water *** ******* ****.
* *** **** ****** ** ******* that **** *** ****** **** ***** isn't ******* ********* **** ** ****** very ******* *** *** ****** ***'* keep **, *** ****** ******* *** reader ******* ** **** * ******* that ***** ** ** **** ******** it's ***** *** ****** *** * period ** ****, *** ** *** issuing *** **** *******.
** **** ***** ***** *** ****** the ****** ** ******* ** ******** the ****** *** ****** *** ** line ** ****, *** ****** * soffit ** ***** ************* *********, ***** two *********** *********:
*. ****** **** ********* *
*. *** ** **** ***** ****** directional *** ********-**** ********-****** ********* ********
** ***** ** ******* **** ******, two ****** **** ** ** ****:
*. *** ***** ** ****** ****** must ** **** ** "****" *** reader, ********* ** ***** *** **** that *** ****** ******, *** ****, not **** ***** ** **** *** appropriate ********.
*. *** ****** **** ** **** to "****" *** ***** ** ****** device, ********* ***** ** ** *** to **** *** "*****" ******* *** stop ***** **** **'* *****.
** **** ***** ****, *** *** test **** ** **** *** **** any *** ** ******* ****** ** running *** *** ****** ************* ******* and ******** *** *******. ** *** can *** *** ****** ** ******** when *** **** *** **, **** you *** ******** **** **. *** range ***** ** ******** ** *** wall ******** *****-********** ********, *** ******** speaking, **** ******** ** *******. (***** absorbs ***** ***** ** *** *.**** spectrum.) ************* * ***'* **** * number ** ******* *** **** **** because *** ********* *** ** *******.
** *** ** **** ****** **** goes, *** * *** *** ** "very **** ***". ***** *** ******* out ***** **** ***** ************* ********* beyond ***, ******* **** ** ******* two ********* ******** ******* **** *** both ***** ******* ********. ***** *** BLE ****** **-***** ** ***** ** antenna **** **** **** ******* *****, that **** *** *** ******. * would ****** * ********** ***-********** *** unsupported ***** ** * ****** ******* meters ***** ***** *************. ***** *** Signo's *** ******* ** ** * different ****** **** *** **** ******* included ** *** **** ******** *******, the ******* ***** ***** ****** ****** between *** *** ********.
** ***** *****, *** ***** ********* mitigating ********** ********* ********* ** *** reader **** ***** ** ***** ***** the ********* ** ***** *** ********?
******** *** ************ ***** ** *** reader *** ****. *** ***** *** be ******** ** ****** *******. ******** that ******* ****** ** *** *.**** spectrum **** ****.
****, *** **** ** ****** **** ? :)
******* ** **** *** **** ** "suck". :-)
**'* * **** **** ****** ** not **** **** *** ******* **** to ** *****, *** *** ******* as ****. **** **** ***** ************ frequency *** ***** *** **** *******. From ** *********** *********** *** ** consideration ** *** ******* *********** ** chip ********** *** ******** *********** ** radio *****, **'* ******** ******, ******, really ****.
***. * ** ***** ** ******* BLE ** *** ** ******* ***** we ***'* *** ** ******. * am **** ** ********** **** *** be ***** *'* ***** ** **** them ** ****......