Hardware Wallet Troubleshooting FAQs
Mnemonic word generation mechanism
The current industry-wide mnemonic standard is BIP39. BIP39 Mnemonic words are not simply "selected" words from the vocabulary, but are generated based on a strict cryptography mechanism:
Generate random numbers (entropy): The device first generates a period of high-quality random numbers (called "entropy").
Split fragments: Divide this random number into several data segments with a length of 11 bits.
map words: Each data segment will strictly correspond to a specific word in the BIP39 standard vocabulary (a total of 2048 fixed words).
Because the generation and mapping of each fragment is independent and completely random, fragments at different positions may be mapped to the same word in the vocabulary. This is like drawing 12 or 24 times from a deck of 2048 cards. After each draw, the cards are put back and drawn again. Drawing duplicate cards is a normal probability event.
What is the probability of repeated words?
Since the same 2048-word vocabulary is randomly selected each time, the theoretical probability of at least one repeated word is as follows:
12 word mnemonics: The probability of at least one repeated word is approximately 3%(approx. 1/33).
24 word mnemonics: The probability of at least one repeated word is approximately 12%(approximately 1/8).
In other words, if you generate a 24-word mnemonic, on average, you will have a duplicate word 1 out of every 8 times you generate it.
Does repeating words reduce security?
No.
The security of a mnemonic phrase depends on its underlying Number of random entropy bits (128 bit or 256 bit), rather than whether the superficial words are repeated. Even when repeated words appear, the underlying randomness remains intact. The repetition phenomenon is just a natural manifestation of "true randomness", and it will not weaken the security of cryptography.
UKey How does the hardware wallet ensure the randomness of the mnemonic phrase?
UKey The hardware wallet fully guarantees the security and true randomness of mnemonic phrase generation from the underlying hardware to the software code:
Open source and transparent:UKey's firmware and code are completely open source, publicly auditable, and the security mechanism is transparent and visible.
Financial grade security chip: The device has a built-in EAL 6+ certified security chip (SE).
true random number generator: A hardware-level True Random Number Generator (TRNG) is used to generate underlying entropy, and the quality of its entropy source has undergone strict security certification and evaluation.
Operation suggestions
We recommend that you use device-generated mnemonics containing repeated words with confidence and copy them on physical media for safekeeping in accordance with security regulations.
If you are personally uncomfortable with mnemonics containing repeated words, you can choose to regenerate a new set of mnemonics directly during the initialization process of the UKey hardware wallet. And make an offline backup of the newly generated mnemonic words.