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Bip39 24 words vs slip39 20 words: which is stronger?

Seed Phrases Under Fire | BIP39 vs. Slip39

By

Liu Wei

Jul 3, 2025, 11:46 AM

Edited By

Omar Khan

3 minutes reading time

Visual representation showing BIP39's 24-word seedphrase and Slip39's 20-word seedphrase, highlighting their differences in length and security features.
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A fierce debate is heating up among crypto enthusiasts about the security levels of seed phrases, with many arguing that BIP39's 24-word seed phrase offers superior security compared to Slip39's 20-word option. As experts weigh in, understanding the implications could change how people protect their digital assets.

The Stakes of Seed Phrase Security

Seed phrases serve as gateways to crypto wallets, and their security is paramount. Recent discussions on forums highlight the overwhelming odds against someone cracking these phrases. A user emphasized, "A 24-word seed phrase is uncrackable," referring to the astronomical possibilities associated with seed phrase combinations.

While both seed phrases are reported as hard to crack, the BIP39 option boasts a whopping 256 bits of entropy, significantly higher than Slip39's 128 bits. This discrepancy in entropy translates to heightened security. One forum commenter pointed out, "Nobody can possibly guess or crack a Bitcoin seed phrase It's a brute-force nightmare!"

Odds of Guessing Seed Phrases Are Insane

Drawing comparisons to lottery odds, the statistics are staggering:

  • For a 12-word seed phrase, the odds of guesswork are approximately 1 in 340 trillion.

  • Increase that to 24 words, and weโ€™re looking at 1 in over 115 octillion.

This gulf in odds paints a clear picture of security. Another engaging quote underlines this point: "Adding just one more word drastically worsens the guessing odds."

Understanding Brute-force Attempts

Some users clarify that cracking a seed phrase isn't just about guessing.

"Each combination leads to a new wallet. One has to check if anything is in such a wallet a brute-force attempt requires testing countless combinations."

Currently, no computer has the capability to tackle the sheer number of potential seed phrases. If a passphrase is involved, the difficulty spikes even higher.

Sentiment Among Users

Sentiment in conversations remains largely confident, with users emphasizing that

  • Cracking either phrase is virtually impossible.

  • Many support BIP39 as the gold standard for security.

  • Concerns about possible overlaps in seed phrases were raised in a thoughtful discussion.

Key Takeaways

  • ๐ŸŒ BIP39's 24-word seed phrase has 256 bits of entropy, making it harder to breach.

  • ๐Ÿ’ฐ The odds of guessing a 12-word phrase are staggering at 340 trillion.

  • ๐Ÿ“‰ "Cracking" a Bitcoin seed phrase through brute force is impractical currently.

As the crypto landscape evolves, discussions around security mechanisms like these will undoubtedly shape how people store and protect their assets. It's clear: for now, BIP39 holds the crown in the realm of seed phrases.

Future Landscape of Seed Security

With the crypto realm evolving rapidly, the conversation around seed phrase security will only intensify. There's a strong chance that as more people adopt cryptocurrencies, security measures will become a focal point. Experts estimate that in the next few years, new algorithms may emerge aiming to enhance seed phrase security even further, possibly matching or even exceeding BIP39โ€™s model. We could see traditional wallets being replaced by more advanced solutions, with about 65% probability that users will favor safer, more innovative options moving forward. Ultimately, the path of least resistance in security will likely point towards systems that prioritize not just technology but user education and awareness.

A Look Back to the Great Encryption Wars

The current discourse about seed phrases echoes the Great Encryption Wars of the late '90s. Back then, the battle over cryptography standards and their security significance mirrored todayโ€™s debates in the crypto community. Just as tech companies and governments grappled over the balance between privacy and security, todayโ€™s crypto enthusiasts and experts are facing similar crossroads. In both cases, public opinion and technological advancements shifted the balance of power, leading to stronger encryption protocols and, ultimately, greater security for individuals. As we navigate through these discussions today, the lessons from that period remind us that the stakes are high and the quest for secure digital assets is a continual journey.