topic Registered
Verified 2026-09-19 · registry updated 2024-02-16

HTTP registry: ADLER32

The ADLER32 algorithm is a checksum specified in RFC1950 "ZLIB Compressed Data Format". The 32-bit output is encoded in hexadecimal (using between 1 and 8 ASCII characters from 0-9, A-F, and a-f; leading 0's are allowed). For example, ADLER32=03da0195 and ADLER32=3DA0195 are both valid checksums for the 4-byte message "Wiki".

Integrity registry values define algorithms or message metadata used to detect alteration of HTTP content or representations. ADLER32 is registered in HTTP Digest Algorithm Values. Defining reference: rfc1950.

httpregistryhttp-dig-alghttp-dig-alg-1

Identifier (http)

ADLER32

The ADLER32 algorithm is a checksum specified in RFC1950 "ZLIB Compressed Data Format". The 32-bit output is encoded in hexadecimal (using between 1 and 8 ASCII characters from 0-9, A-F, and a-f; leading 0's are allowed). For example, ADLER32=03da0195 and ADLER32=3DA0195 are both valid checksums for the 4-byte message "Wiki".

Prefer approved algorithms, define exactly which bytes are covered, and account for encoding, ranges, canonicalization, and replay.

This registry value is currently marked active by IANA. Follow the defining specification before sending, accepting, or proxying it.

IANA registry: http-dig-alg/http-dig-alg-1

Registry reference: rfc1950

Permalink: https://merginit.com/reference/http/registry/http-dig-alg/http-dig-alg-1/adler32-60