Signal 的簡訊花費在 $6m/year

Signal 的「Privacy is Priceless, but Signal is Expensive」這篇 PR 稿裡面提到了各項支出,Hacker News 上的討論在「Privacy is priceless, but Signal is expensive (」這邊可以翻到。

裡面可以看到目前的數字 (以 2023 年十一月推算):

Storage: $1.3 million dollars per year.
Servers: $2.9 million dollars per year.
Registration Fees: $6 million dollars per year.
Total Bandwidth: $2.8 million dollars per year.
Additional Services: $700,000 dollars per year.

Current Infrastructure Costs (as of November 2023): Approximately $14 million dollars per year.

我比較感興趣的有幾塊,一個是標題提到的簡訊,在「Registration Fees」這個段落的說明裡可以看到列了兩個項目,一個是下載 Signal 的費用,另外一個是簡訊 SMS 認證的費用:

Signal incurs expenses when people download Signal and sign up for an account, or when they re-register on a new device. We use third-party services to send a registration code via SMS or voice call in order to verify that the person in possession of a given phone number actually intended to sign up for a Signal account.

這邊有些要確認的,下載軟體的頻寬應該是包括在 Total Bandwidth... 而且推敲起來,金額應該不算大:

  • 手機上的應用應該是由 AppleApp StoreGooglePlay 平台提供,不需要 Signal 提供頻寬下載。
  • 桌面應用端的部分,無論是 Windows、Mac 還是 Linux 的平台,看起來是透過 下載,這個名稱目前是指到 Cloudflare 上面,透過 traceroute 看起來不是 premium account (HiNet 用戶是導去美西的 SFO 機房),也許是 Cloudflare 的贊助帳號?

所以我會先假設這邊 $6m/year 的費用應該都是 SMS,在後面這段看起來也有提出來:

The cost of these registration services for verifying phone numbers when people first install Signal, or when they re-register on a new device, currently averages around $6 million dollars per year.

另外會這麼高也是因為現在 SMS pumping 很流行,也就是攻擊者與電信商合作 (或是同一組人),透過假造大量的認證需求,讓 app 後面的公司需要付大量的簡訊費用:

另外一個感興趣的是頻寬的部分,裡面有提到有一個比較吃頻寬的項目,是處理不在通訊錄上面的通話或是視訊。這邊 Signal 為了避免 IP address 的洩漏,會避免直接讓兩邊接通,而是透過 relay 接通:

To take one example, Signal always routes end-to-end encrypted calls from people who aren’t in your contacts through a relay server that obscures IP address information.

光這部份大約是 20PB/year 的量,費用約 $1.7m/year (上面有提到整個頻寬費用約 $2.8m/year):

At current traffic levels, the amount of outbound bandwidth that is required to support Signal voice and video calls is around 20 petabytes per year (that’s 20 million gigabytes) which costs around $1.7 million dollars per year in bandwidth fees just for calling[.]

而最大的費用還是各種人事支出的部分 (i.e. 經濟規模還沒有大到反過來),佔 $19m/year:

In total, around 50 full-time employees currently work on Signal[.]

To sustain our ongoing development efforts, about half of Signal’s overall operating budget goes towards recruiting, compensating, and retaining the people who build and care for Signal. When benefits, HR services, taxes, recruiting, and salaries are included, this translates to around $19 million dollars per year.

在 Hacker News 上有人貼了「Signal Technology Foundation - Nonprofit Explorer - ProPublica」這個,這邊有申報資料可以翻,比 PR 稿上面細。

ISP 偽造出合法的 SSL certificate,對放在德國的 進行 MITM 監聽

標題有點複雜,先講一下 http-01 認證,這是目前 Let's Encrypt 上最常被使用的認證方式,是透過 HTTP 協定完成認證,你只要能回答 的內容就能過。

一般來說,這個 HTTP 位置只有這台伺服器的 owner 才有辦法提供,也就能確保不是任何人都可以申請。

但因為這邊走的是 HTTP,對於 ISP 這種比較特別的身分來說,他可以從中架設 HTTP 的 MITM Proxy 做到這件事情。

而有了合法的 SSL certificate 之後,中間的 MITM Proxy 就不只能聽 HTTP 了,還可以聽 HTTPS 的內容 (甚至修改內容)。

這次發生的事情就是在德國的 LinodeHetzner 機房內的服務,俄羅斯最大的 XMPP 服務 被搞出這件事情 (XMPP 是一個開放協定,不熟的話可以想像成類似 Line 或是 Telegram 的服務,但 XMPP 是開放協定,可以用自己喜歡的軟體連上):「Encrypted traffic interception on Hetzner and Linode targeting the largest Russian XMPP (Jabber) messaging service」。

他們在 Hetzner 的伺服器上有發現 network offline 的訊號:

[Tue Jul 18 12:58:29 2023] igb 0000:04:00.0 enp4s0: igb: enp4s0 NIC Link is Down
[Tue Jul 18 12:58:48 2023] igb 0000:04:00.0 enp4s0: igb: enp4s0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX

而在這個 network offline 的時間不久後 Let's Encrypt 發出了 與 的 SSL certificate ( 上可以查到,在 99976947049997621208):

18 July 2023 issuing time is about the same when Hetzner server has lost network link for several seconds.

這些徵兆符合改接到 MITM Proxy 上的行為。

這次的事情很大條,因為這些伺服器是在德國,不是在俄羅斯... 事情才剛開始被報導出來,後續得繼續追蹤,而且應該也會促成新的機制被引入?

Slack 宣佈漲價

Slack 宣佈了漲價的計畫:「Everything you need to know about our first price change and plan updates」。

從今年九月開始漲價,Pro 的月費從 US$8 漲到 US$8.75 (+9.375%),年費從 US$80 漲到 US$87 (+8.75%):

On September 1, 2022, monthly Pro plans will increase from $8 USD to $8.75 USD per user per month, and annual Pro plans will increase from $6.67 USD to $7.25 USD per user per month (pricing for other countries is available here).

現有用戶有一次用原價 renew 一年的機會:

Current customers on an annual Pro plan can lock in the existing annual rate of $6.67 USD per user per month for another year by early-renewing the annual Pro plan before September 1.


幾個其他 Teams 的替代方案 (但還是連到 Teams 伺服器)

這邊講的替代方案不是換掉 Teams,而是找其他的方法連上 Teams 伺服器,畢竟用 Teams 的人大多都沒得選...

在「Teams is killing my Mac every day (」這邊看到的一些資料可以嘗試,裡面有很多抱怨 Teams 的問題,但還是有些人有給出一些 workaround。

大家主要遇到的問題除了 CPU 吃很兇以外,另外就是記憶體這塊。

一種方法是是用 Edge 瀏覽器的 extension 來跑,我本來想看看 Linux 上的 Brave 能不能裝,但沒有看到對應的安裝連結,大概是 Edge 限定:

If you don't want to use the Microsoft Teams app (which uses a lot of resources), you can:

1. Install the Microsoft Edge Web browser on your Mac

2. Log into

3. Click ... > Apps > Install this site as an app

This will create an Edge app for Teams that uses almost no resources but has feature parity with the regular Microsoft Teams app.

We tell all of our students to do this, and it has solved all Microsoft Teams performance issues on student Macs (both Intel and Apple Silicon).

另外有人提到其實官方是有放 M1 的 preview 版本的,雖然不是正式版,但總是比 Intel 版本會好一些:

If you're running an Apple Silicon Mac you can get an early build of Teams osx-arm64 from the exploration build link listed here.[0]

I've been running a daily build for a few weeks and it's noticeably better than the Intel build on an M1 Pro. It launches in half the time and feels far more responsive (probably due to not needing to use the Rosetta JIT for Electron). That said it's still a daily "exploration" build so YMMV.



Can confirm it is snappier on a M1 Macbook Pro and using *less* RAM, maybe about 10% less.

但據說這個 preview 版本在自我更新時會跳到 Intel 版本,還要再找一下 workaround 關掉自動更新:

How do you prevent it from automatically updating to the Intel version? I keep downloading the preview builds and they keep getting updated.

後面還有看到有人說他直接實體隔離,把這些肥滋滋的 app 跑在另外一台 Mac 上,然後透過 Universal Control 使用,大多數的情況下都夠用,真的有需要分享畫面時再跑在自己機器上,用完就可以關掉:

Thanks for the tip. I'll give this a try!

For work, I have to run Microsoft Teams, Slack, and Discord. Of those 3, Slack surprisingly uses the least amount of memory (~700 MB), and Teams uses the most (~1.5 GB). I dusted off an old Intel Mac (literally) and interact with it using Universal Control. It only runs those 3 chat apps + mail. It's turned out to be a great way to offload resource hogs and as an added benefit, it minimizes distractions. I'll occasionally glance at the dock to see if there are any notification badges, whereas on my main Mac, I'd feel compelled to deal with notifications immediately.

When I have to share my screen or focus on a conversation, I'll fire up one of those 3 apps on my main (M1) Mac and quit it when I'm done.

Universal Control still feels rough around the edges, but it has saved me from ditching my Macbook Air and shelling out for an M1 Macbook Pro. Sometimes there are issues with reconnecting to the Intel Mac, but it seems to resolve itself if I wait a bit or turn off/on wifi.

大家都在找方法 XDDD

找機會研究 Zulip...

Hacker News 上看到「Mattermost – open-source platform for secure collaboration (」這篇,結果最高分的 thread 上面大家都在討論 Mattermost 的缺點,然後大家提到 Zulip 是個不錯的方案...

先前用過兩次 Mattermost,一次是獨立自己架起來的版本,另外一次是 bundle 在 GitLab 裡面的。後面這次用的時候有種濃濃的 copycat 的感覺 (在同公司的 Focalboard 也是類似的感覺),後來砍掉就沒繼續再看了。

從 Hacker News 上討論可以看到只有一部份 open source:

And not only that, Zulip is 100% FOSS, wherea Mattermost is Open Core, so the Open Source portion is missing key features.

來找機會架 Zulip 起來玩看看...

Telegram 推出 Premium 方案

Telegram 宣佈推出 Premium 了:「700 Million Users and Telegram Premium」。看了一下有點長度,就直接放 iThome 的報導:「Telegram正式推出付費訂閱服務Telegram Premium」。

更新 Telegram 後就會在 Settings 裡面看到 Premium 的設定可以選,然後看起來走 IAP,我自己是在台灣的 iOS 上面買,NT$160/mo,裡面提到的功能基本上都用不到 (大概只有 no ads),但還是買起來...

Mattermost 推出了 ESR 5.31

在「Support for ESR 5.25 is ending」這邊看到 Mattermost 新的 ESR (Extended Support Release) 釋出了,也就是 5.31 版。

不過看了一下發現 support 期間還是很短,一般的 release 是三個月,ESR 也才九個月:

另外一個大問題是在行動平台上多帳號的支援,官方在「Mobile Apps FAQ」有提到這個問題,然後也有解釋技術上的問題,不過從 issue tracking system 可以看到官方對這個 feature 進展不怎麼快:

At the moment, we only support connecting to one server at a time; however, we are aware that this is one of the top feature requests for the mobile app. We are currently investigating some technical challenges, such as how to handle push notifications coming from multiple servers. To follow our progress on this feature, you can join the RN: Multi-Server channel on our community server.


Telegram 開始跟俄羅斯政府合作

雖然路透社的標題寫的像是俄羅斯政府是因為放棄封鎖 Telegram,不過讀一下內文就會發現完全不一樣:「Russia lifts ban on Telegram messaging app after failing to block it」。

報導上看起來是俄羅斯政府說 Telegram 會與政府合作打擊恐怖份子,所以解封 (先不要管「恐怖主義」之類的詞,這常常是打擊異己時用的詞彙):

Some Russian media cast the move as a capitulation, but communications watchdog Roskomnadzor said it had acted because the app’s Russian founder, Pavel Durov, was prepared to cooperate in combating terrorism and extremism on the platform.

“Roskomnadzor is dropping its demands to restrict access to Telegram messenger in agreement with Russia’s general prosecutor’s office,” it said in a statement.

現在的重點會在於 Telegram 會不會解釋,以及解釋的內容 (目前是還沒有):

There was no immediate reaction from Telegram or Durov.

因為劇本有可能是 1) Telegram 根本沒跟俄羅斯政府接觸,純粹是俄羅斯政府想搞 Telegram,或是 2) 有接觸,但談的跟報導的差很多,或是 3) 就是 Telegram 放棄掙扎了。

後續的 Telegram 回應會是重點,另外 end-to-end encryption (E2E Encryption) 的承諾會有什麼樣的變化也會是重點。

我猜測比較可能的應該是有合作,但控制權在 Telegram 手上,並不是直接讓俄羅斯政府碰 Telegram 的內部系統,不過一切都還得等後續的消息才能確認...

用事實查核中心的 RSS feed 加上 IFTTT 自動通知到 Line/Telegram/... 內


事實查核中心的官網用的是 netiCRM 這個平台 (看起來底層是 Drupal),而在 HTML 頁面的開頭可以看到 RSS 1.0 的 xmlns 宣告:


本來想說直接用 feed 接到 IFTTT 就好了,不過 HTML 頁面上沒有放 feed entry 讓閱讀器可以直接找到 feed 本身,也就是像這樣的標籤資訊:

<link rel="alternate" type="application/rss+xml" title="Gea-Suan Lin&#039;s BLOG &raquo; Feed" href="" />
<link rel="alternate" type="application/rss+xml" title="Gea-Suan Lin&#039;s BLOG &raquo; Comments Feed" href="" />

找了一下 Drupal 的設定慣例,發現 feed 可能會放在 /rss.xml 這個位置,測了一下發現順利在 這邊看到 feed,接下來就可以加進 IFTTT 了:

給有興趣想要用 feed 做些事情的人參考看看,像是加到 Line 或是 Telegram 的群組裡面,或是放到 Slack channel 裡面 (Slack 裡應該可以直接在某個 channel 裡用 /feed add 把這個 feed 加進去)。

架設 MTProxy 加快 Telegram 的速度

在台灣如果是透過 HiNetTelegram 是沒什麼問題 (不需要翻牆),不過連結的 preview 以及圖片影片讀取的速度實在很慢,試著在 GCP (彰濱機房) 跟 Vultr (東京機房) 上架 Proxy 測試看看,發現速度都改善很多...

這邊用的是官方提供的 MTProxy,我把安裝的懶人包放在自己的 wiki 上了:「MTProxy」,在 AWS 或是 GCP 上安裝時,因為網卡拿到的是 Private IP 而非對外的 Public IP,需要指定 --nat-info 告訴 MTProxy 要針對協定裡面的 IP address 另外處理。