--- title: "Remove md5 as a module checksum hash" url: https://daily.dev/posts/remove-md5-as-a-module-checksum-hash-9pyglzkzr source_url: https://erlangforums.com/t/remove-md5-as-a-module-checksum-hash/5879 type: article source: "Erlang Forums" published: 2026-08-24T19:40:43.177Z updated: 2026-08-24T19:41:08.585Z tags: ["performance", "compiler", "erlang"] reading_time: 8 upvotes: 1 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Remove md5 as a module checksum hash **[Erlang Forums](https://daily.dev/sources/erlangforums)** · 8 min read · 1 upvotes · 0 comments ## Summary A proposal on the Erlang forums argues for replacing MD5 with a modern non-cryptographic hash like XXH3-128 for BEAM module checksums, citing benchmarks on OTP 29.0.5 showing checksum time dropping from 19.5ms to 0.3ms when loading 168 stdlib modules, a meaningful chunk of VM boot time for short-lived processes. The proposal outlines deprecating the md5 field in module_info/1, adding a new checksum field returning an algorithm/digest tuple, and eventually returning undefined for md5. It also raises open questions about migrating MD5 usage in ETF's NEW_FUN_EXT Uniq field, including distribution protocol negotiation between nodes during a transition period. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How much faster is XXH3-128 than MD5 for hashing Erlang BEAM module checksums? XXH3-128 reduced checksum calculation time from about 19.563ms to 0.327ms when loading 168 stdlib modules on OTP 29.0.5 (Linux/aarch64, one scheduler), a roughly 60x speedup. This cut the MD5 checksum share of VM boot time from 11.17% to 0.20%, saving about 13-19ms of boot time depending on the machine, which matters for short-lived VM instances like browser-compiled BEAM. _Anyone optimizing Erlang VM boot times can track proposals like this hashing change on daily.dev._ ### What changes are being proposed to remove MD5 as the Erlang BEAM module checksum algorithm? The proposal suggests deprecating the md5 field in module_info/1, adding a new beam_lib:checksum/1 function and checksum field returning an {algorithm, digest} tuple, and eventually returning undefined for the md5 field after a deprecation period. It also flags open questions about migrating MD5 usage in ETF's NEW_FUN_EXT Uniq field, which would require distribution nodes to negotiate hash algorithms during a transition period. _Erlang maintainers weighing this checksum migration can follow the discussion's progress on daily.dev._ ## Similar posts on daily.dev - [Patch package OTP 29.0-rc2 Released](https://daily.dev/posts/patch-package-otp-29-0-rc2-released-43r5cevzp) · Erlang Forums · 0 upvotes · 0 comments - [Expose more of OpenSSL’s KDFs in \`crypto\` \(HKDF, scrypt, Argon2\)](https://daily.dev/posts/expose-more-of-openssl-s-kdfs-in-crypto-hkdf-scrypt-argon2--onzohlz6x) · Erlang Forums · 0 upvotes · 0 comments --- Tags: [#performance](https://daily.dev/tags/performance), [#compiler](https://daily.dev/tags/compiler), [#erlang](https://daily.dev/tags/erlang) [View this post on daily.dev](https://daily.dev/posts/remove-md5-as-a-module-checksum-hash-9pyglzkzr)