Google Docs is not end-to-end encrypted because the merge has to happen somewhere

Key custody is the part that decides everything downstream. Encryption at rest protects the disks in the provider's building and TLS protects the hop from your browser to their front door, but the provider holds the decryption keys in both cases, so neither narrows what the company itself can read ^[2]. The honest reading of "encrypted" on a collaboration vendor's page is a statement about attackers outside the building.

The reason sits in the merge algorithm rather than in any security decision. Live editing, the kind where a colleague's cursor moves in front of you, needs something that processes edit operations and reconciles two people typing into the same paragraph, and both dominant approaches, operational transformation and CRDTs, were designed around a server or at minimum a shared relay doing that work ^[13]. Take plaintext away from the server in one of those designs and you lose more than conflict resolution: the search index, the preview thumbnail and the live spell-checker were built on the same access ^[3].

CRDTs are the exception worth knowing about, because they merge deterministically from the data structure itself, with no arbitration required ^[5]. That property is what lets encrypted operations be relayed as opaque blobs and merged on each client after decryption ^[6]. So the cryptography is not the blocker. A handful of newer products, mostly encrypted note-taking and password-manager-adjacent tools, already ship sync built this way, while mainstream office suites have not ^[14]. What is left is migration cost and a feature bill: retrofitting a CRDT-and-encryption architecture onto a decade of shipped product is work most vendors have declined, and server-side full-text search either gets meaningfully harder or moves to the client ^[7][12].

Search appears on both sides of the source's argument, named as a reason vendors do not build this and as the most common casualty for buyers who pick a tool that did ^[7][9]. In a procurement conversation that is the whole negotiation. Most other things in a document suite have some client-side substitute. Workspace-wide search does not have a good one yet, which is why the feature that sells the suite is also the feature that keeps the plaintext on the server.

A caveat about where this comes from: the argument is published by Haven, which sells encrypted email and chat and does not ship collaborative documents at all ^[10], and which says features requiring server-side plaintext get built without it or do not get built ^[11]. That is a vendor describing a constraint it has chosen to live inside, and it should be read with the discount that implies. The technical account still holds, and it leads somewhere narrow rather than sweeping. For meeting notes and drafts that will be public anyway, provider access rarely matters in practice; for legal strategy memos or unreleased financial terms, where "the vendor got a subpoena or got breached" is a planning scenario, it is the only property that matters ^[8].