mnemonicToEntropy

Converts a BIP-39 mnemonic phrase back to its original entropy.

This function validates the mnemonic by:

1. Checking word count (must be 12, 15, 18, 21, or 24)

2. Verifying all words exist in the word list

3. Validating the checksum

Algorithm:

1. Split mnemonic into words

2. Look up each word's index in word list (O(1) HashMap lookup)

3. Convert indices to 11-bit binary strings

4. Concatenate all bits

5. Split into entropy bits and checksum bits

6. Verify checksum using constant-time comparison

7. Return entropy bytes

This function is suspend because JavaScript requires async initialization of the cryptographic library for SHA-256 checksum validation. On JVM and Native platforms, the suspend keyword has zero overhead.

Parameters

Throws

val mnemonic = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
val entropy = MnemonicUtils.mnemonicToEntropy(mnemonic)
// entropy is 16 bytes of zeros