Frequent !TSF:MSG:SIGN FAIL issues

[erangaj]

I have a motion sensor + repeater node and a rpi gateway. rpi gateway is compiled with "--my-signing=software" and "--my-signing-request-signatures" flags. Below settings are configured in the node.

#define MY_SIGNING_SOFT
#define MY_SIGNING_SOFT_RANDOMSEED_PIN 7
#define MY_SIGNING_REQUEST_SIGNATURES

As shown below I sometimes see seemingly random, but frequent "!TSF:MSG:SIGN FAIL" messages

***************** Motion:1
268194 TSF:MSG:SEND,1-1-0-0,s=4,c=3,t=16,pt=0,l=0,sg=1,ft=0,st=OK:
268201 TSF:MSG:READ,0-0-1,s=255,c=3,t=17,pt=6,l=25,sg=1:837C71E827A0793D6D50A9666BE92B0DF1D500008BA9900E91
268296 TSF:MSG:SEND,1-1-0-0,s=4,c=1,t=16,pt=0,l=1,sg=1,ft=0,st=OK:1
***************** Motion:0
332350 !TSF:MSG:SEND,1-1-0-0,s=4,c=3,t=16,pt=0,l=0,sg=1,ft=0,st=NACK:
332356 !TSF:MSG:SIGN FAIL
332359 TSF:MSG:READ,0-0-1,s=255,c=3,t=17,pt=6,l=25,sg=1:8974C67AA563CB9ADFF58F8B31CC4760119CAB95239CA3C4F9

How can I get rid of this issue? Thanks in advance.

[Anticimex]

@erangaj as explained on the signing troubleshooting guide, NACKs are caused by radio problems and not signing problems.
The reason NACKs might be more frequent with signing is because the message size gets maxed out by the signature, and thus becomes "harder" to transmit/receive.

[erangaj]

Thanks. I went through all the recommendations and tried different radio modules. But the result was the same. The NACKs happen when sending from node to the gateway but not in the opposite direction. Finally decided sign the messages going from the gateway to nodes only and leave node to gateway messages unsigned. It is a compromised solution, but it is enough for my needs. (recompiled the gateway with "--my-signing=software" flag but not "--my-signing-request-signatures" flag, nodes were not changed)

[Anticimex]

@erangaj ok, well in fact you still use big messages in both directions as the sender of the signed message will request a nonce from the receiver which also will be a full size message. But of course it mean there will be fewer big messages in transit overall.

[erangaj]

@Anticimex Yes, but it is running for hours. Never saw the issue again.

[Anticimex]

@erangaj