{
  "id": 11242231,
  "title": "Git 3.0's upcoming SHA-256 default will be a costly mistake",
  "url": "https://urgent.news/2026/10/01/git-3-0s-upcoming-sha-256-default-will-be-a-costly-mistake",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-10-01T16:57:03.000Z",
  "source": {
    "name": "Hacker News",
    "slug": "hacker-news",
    "url": "https://blog.gitbutler.com/git-3-sha-256"
  },
  "original_language": "en",
  "account": "The upcoming Git 3.0 release is set to introduce SHA-256 as the default content hashing algorithm, which Git has used as SHA-1 since its inception in 2005. This change, though touted as providing stronger security, may prove to be an expensive and unnecessary global nightmare.\n\nThe argument against SHA-1 is that it has been considered semi-broken since 2017, when collision attacks were published (SHAttered, SHA-1 is a Shambles). However, these attacks, while theoretically possible, are not practically exploitable, unlike the theoretical concern with SHA-256.\n\nGit's SHA-1 algorithm has never produced two different files with the same hash, which would be considered a collision. This process, known as a collision attack, is theoretically possible with SHA-1 but not with SHA-256. However, a second-preimage attack, where an attacker creates a malicious file with the same hash as a benign one, is considered more concerning. While this attack is theoretically possible with SHA-1, it is highly improbable with SHA-256.\n\nDespite these theoretical risks, the shift to SHA-256 may cause significant inconvenience and cost for the vast number of Git repositories worldwide. The cryptographic integrity that SHA-1 provides, by hashing potentially millions of file contents, trees, and commits, could be lost with the switch to SHA-256. This change could lead to a significant disruption for users and developers, with little to no practical benefit.",
  "summary": null,
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}