Which hash-based algorithm for storage deduplication provides the lowest risk for hash collisions?

AES-256 is a symmetric encryption cipher, not a hashing algorithm - it is used for data confidentiality, not deduplication fingerprinting.

SHA-1 generates a 160-bit hash value, providing a significantly larger hash space than MD5 (128-bit) or CRC32 (32-bit), which directly reduces the probability of two different data blocks producing the same hash. Among the options listed, SHA-1 offers the best collision resistance for storage deduplication purposes.

MD5 produces a 128-bit hash and has well-documented collision vulnerabilities, making it less reliable than SHA-1 for deduplication integrity.

CRC32 generates only a 32-bit checksum designed for error detection in data transmission, not cryptographic uniqueness, and has a very high collision probability.