Predictable RNG Fallback and 32-Bit Reseed in Coldcard Firmware

#1

Post by greyface- » Fri, Jul 31, 2026, 2:19 AM UTC

Predictable RNG Fallback and 32-Bit Reseed in Coldcard Firmware
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Re: Predictable RNG Fallback and 32-Bit Reseed in Coldcard Firmware

#2

Post by 84adam » Fri, Jul 31, 2026, 2:21 PM UTC

Just read an associate of mine lost 10 years worth of bitcoin he'd saved and mined from this Coldcard issue.

Re: Predictable RNG Fallback and 32-Bit Reseed in Coldcard Firmware

#3

Post by johng » Fri, Jul 31, 2026, 3:36 PM UTC

84adam wrote: post #2

Just read an associate of mine lost 10 years worth of bitcoin he'd saved and mined from this Coldcard issue.

So for this to be exploited, all someone needs to know is that your address was generated on one of these vulnerable Coldcards? No physical access is needed, they just cycle through likely seed phrases and bam, they now have wallet control?

Re: Predictable RNG Fallback and 32-Bit Reseed in Coldcard Firmware

#4

Post by raptorhunter22 » Fri, Jul 31, 2026, 5:28 PM UTC

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Re: Predictable RNG Fallback and 32-Bit Reseed in Coldcard Firmware

#5

Post by infofarmer » Fri, Jul 31, 2026, 5:41 PM UTC

johng wrote: post #3

84adam wrote: post #2

Just read an associate of mine lost 10 years worth of bitcoin he'd saved and mined from this Coldcard issue.

So for this to be exploited, all someone needs to know is that your address was generated on one of these vulnerable Coldcards? No physical access is needed, they just cycle through likely seed phrases and bam, they now have wallet control?

They don't need to know that. Your low-entropy seed / private key will be compromised in the brute force enumeration.