InvalidChecksumException

Exception thrown when mnemonic checksum validation fails.

BIP-39 mnemonics include a checksum derived from the SHA-256 hash of the entropy. The checksum is appended to the entropy before encoding to words. When decoding, the checksum is recalculated and compared. A mismatch indicates the mnemonic was corrupted or contains a typo.

Checksum sizes by mnemonic length:

• 12 words: 4-bit checksum

• 15 words: 5-bit checksum

• 18 words: 6-bit checksum

• 21 words: 7-bit checksum

• 24 words: 8-bit checksum

Recovery actions:

• Double-check spelling of each word

• Verify word order is correct

• Ensure using the correct word list language

Example:

try {
    // Mnemonic with incorrect last word (checksum word)
    val m = Mnemonic.from(
        "abandon abandon abandon abandon abandon abandon " +
        "abandon abandon abandon abandon abandon wrong"
    )
} catch (e: InvalidChecksumException) {
    println("Checksum failed: ${e.message}")
    println("Please verify your mnemonic phrase for typos")
}

See also:

• InvalidWordException for words not in the word list

• InvalidMnemonicException for general mnemonic errors

• Sep05Exception base class

Parameters