RIPEMD-160 Overview

Why Learn About RIPEMD-160?

The other important hash function used in BSV is RIPEMD-160.

• You don’t need to know its inner workings to understand Bitcoin.

• But seeing its design philosophy and history helps highlight why it’s trusted and still relevant.

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A Brief History of RIPE (Race Integrity Primitives Evaluation)

In the 1990s, the European Union established the RIPE consortium to develop better integrity primitives (cryptographic tools to ensure data integrity).

At the time:

• The most popular hash functions were MD4 and MD5, created by Ron Rivest.

• RIPE evaluated these and proposed RIPEMD, a stronger version of MD4.

👉 RIPEMD essentially ran two parallel versions of MD4 with improvements to bit shifts and word ordering.

Shortly after, SHA-1 was published by NIST as an MD5-based improvement.

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RIPEMD-160

In 1995, cryptographer Hans Dobbertin found collisions in the original RIPEMD.

• In response, Dobbertin et al. (1996) proposed RIPEMD-160 and RIPEMD-128.

• Both are still considered secure hash functions today.

Key changes in RIPEMD-160:

• 160-bit output (longer digest for stronger security).

• Five rounds of compression (instead of three).

• Carefully chosen bit shifts (5–15 bits).

• Each message block rotated by different amounts.

• Shifts and constants chosen to avoid exploitable patterns.

Performance trade-offs:

• ~15% slower than SHA-1.

• Half as fast as the original RIPEMD.

• Four times slower than MD4.

• On modern processors, this performance hit is negligible.

👉 Design philosophy: Make the minimum necessary changes to strengthen RIPEMD while preserving confidence from MD4, MD5, and RIPEMD research.

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Use Cases

• In Bitcoin (and therefore, BSV), RIPEMD-160 is combined with SHA-256 to produce HASH-160 (used in address creation).

• Outside Bitcoin, it is notably used in PGP (Pretty Good Privacy) for email encryption.

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✅ Summary: RIPEMD-160 is a secure, reliable, and efficient hash function that balances proven design principles with increased security, making it suitable for long-term cryptographic use.