Hahahahahahaha. Indeed!
@leoncowle good grief - even if they don't know *why* it's significant you'd expect someone writing about computery topics to at least have a feel that the number is special and ask a colleague if it's meaningful, even if just because it comes up so often.
@kimvanwyk @leoncowle Oh, I remember this. They "fixed" it after people complained, and somehow made it about ten^H^H^Height times worse: https://www.independent.co.uk/tech/whatsapp-group-chats-bigger-maximum-size-256-people-users-a6856491.html
WhatsApp increases group chat size limit to 256 people | The Independent

Bigger groups are now available to all WhatsApp users on iOS and Android

The Independent
@confluency @kimvanwyk Oh. My. Gawd!!! You're not kidding. Mwahahahahahaha!

@leoncowle @confluency @kimvanwyk

I like that they speak of variations.

Shouldn't WhatsApp have picked 255?

Doesn't the question why they picked 256 number make you even more worried if you you understand the significance 😳?

@realn2s The *indices* may go from 0 to 255, but it's still 256 *integers* in total (in this case representing people).
@confluency
Yes, that's my point.
This would mean that the maximum group size is 255 (assuming you need to represent an empty group as well).
WhatsApp increasing the group size to 256 requires 9 bits (and then they could have gone for 511 😜)
@realn2s @confluency We just don’t know where this number comes from. It could also be an id of a specific current member in a group. For example I would assume the encryption stuff to have something like that.

@waldi @realn2s @confluency

I assume it is not actually about the chat itself, but about the double ratchet group key management. It organizes keys in a binary tree, and adding or removing users involves rolling over a key on each level of the tree. 256 means the tree has 9 levels. So, the "oddly specific" number here is 9, and that in turn probably is "just one more than before".