CBP Fundamental Cryptography Concepts 3

Question 1

What is the secp256k1 curve's primary role in Bitcoin?

Accepted Answer

It defines the elliptic curve parameters used for Bitcoin's public/private key pair generation and ECDSA signing

Answer

secp256k1 is the specific elliptic curve standard Bitcoin uses, defining generator point G, prime field p, and order n for key generation and ECDSA.

Question 2

What does it mean when we say SHA-256 produces a 'fixed-length' output?

Accepted Answer

Regardless of input size, SHA-256 always outputs exactly 256 bits (32 bytes)

Answer

SHA-256 always produces a 256-bit output no matter the size of the input — a byte, a megabyte, or a gigabyte all produce the same-length hash.

Question 3

In Bitcoin, RIPEMD-160 is applied after SHA-256 when creating an address. Why is double-hashing used?

Accepted Answer

SHA-256 provides strong collision resistance while RIPEMD-160 shortens the output to 160 bits for practical address sizes

Answer

The combination SHA-256 → RIPEMD-160 (HASH160) reduces the public key to a 20-byte address while benefiting from both algorithms' security properties.

Question 4

What is a 'digital signature' in the context of Bitcoin transactions?

Accepted Answer

Cryptographic proof created with a private key that authorizes spending of specific UTXOs

Answer

A Bitcoin digital signature (ECDSA) proves the spender controls the private key corresponding to the address, authorizing the UTXO spend.

Question 5

Which term describes the scenario where changing even one character of input produces a completely different hash output?

Accepted Answer

Avalanche effect

Answer

The avalanche effect means small input changes cause large, unpredictable changes in the hash output, preventing attackers from deducing inputs from similar outputs.

(CBP) Certified Bitcoin Professional Practice Test

(CBP) Certified Bitcoin Professional Practice Test

CBP Fundamental Cryptography Concepts 3