Some people are asking a good question, how can they trust that Hardware Wallets are randomly generating Bitcoin seed words?
First, whatever device you are using and not just a hardware wallet, but also your smart phone, computer or any other device, you need to have some basic trust or verify everything on your own and that is not always easy.
Generally speaking, hardware wallets that are open source and existed longer time have been examined by many security experts and they are considered safer but none of them is 100% safe.
Hardware wallets are made to simplify things for average newbie, but you should always remember that seed words are more important than your hardware device.
Humans are bad in making anything random so forget about it if you had an idea to pick 24 random words from your head/wordlist and used them as your seed words.
You need to achieve good 256bit entropy or disorder and good old dices or coin flipping are some way to achieve this so you don't have to trust their random number generators.
How are Hardware Wallets doing entropy?Trezor One and T is mixing external entropy from computer with internal entropy from built-in hardware random number generator
RFC 6979, and this can be verified on their github page.
Trezor 3 to be updated...
Ledger wallet is using Random Number Generator from their closed source Secure Element to generate mnemonic seed with AIS 31* certification.
ColdCard have the option for using internal true random number generator from their secure element or to use D6 Dice Rolls that can be verified. Verifiable Seed Generation.
Keystone is using Random Number Generator from their open source Secure Element and it can generate seed with casino-grade dices. Verifiable Seed Generation.
Passport wallet is using Avalanche noise source, an open source true random number generator (one of them is the part of MCU, the other one is in SE). Verifiable Seed Generation.
Bitbox is using five different entropy sources from factory setup, secure element, regular chip, computer and device password, everything is open source and with latest update you can roll dices for verifiable seed generation.
Safepal is using closed source secure element for random number generation with AIS 31* and FIPS PUB 140–2** certification
BC Vault uses built-in hardware gyro sensor and various timings with human shaking the device for random number generation.
Jade wallet is mixing internal entropy from built-in hardware random number generator and various other things with companion app entropy.
Onekey mini uses internal random number generator that satisfies NIST SP 800-90A/B/C; CSPRNG is used to guarante the quality of randomness, which is equivalent to DIEDARD TEST, FIPS 140-2, TEST U01 test criteria.
Ngrave zero is combining data taken from internal TRNG, fingerprint scanner and ambient light captured by the build-in camera.
Specter DIY uses mix of multiple sources of entropy, TRNG of the microcontroller, Touchscreen and Built-in microphones (not yet), that are all hashed together.
SeedSigner DIY creates 24-word BIP39 seed phrase with 99 dice rolls or by taking a digital photo; and it can be be done with coin flips.
RNG Random number generation is a process which, often by means of a random number generator (RNG), generates a sequence of numbers or symbols that cannot be reasonably predicted better than by a random chance.
https://en.wikipedia.org/wiki/Random_number_generationTRNG - True Random Number Generator
HRNG - Hardware Random Number Generator (generates genuinely random numbers)
PRNG - Pseudo Random Number Generator (generates numbers that look random, but are deterministic and reproducable)
Random number generator is used in IT, lottery systems, gaming, for passports and ID cards, smartphones, in NFC and chip manufacturing.
*
AIS 31 certification standard used by Germany BSI
**
FIPS PUB 140–2 certification standard used by US government
work in progress