Move Fast and Roll Your Own Crypto: A Quick Look at the Confidentiality of Zoom Meetings

Learn our description of Zoom’s waiting room vulnerability, in addition to frequently asked question about Zoom and encryption points.

This report examines the encryption that protects conferences in the widespread Zoom teleconference app. We discover that Zoom has “rolled their own” encryption scheme, which has important weaknesses. As well as, we establish potential areas of concern in Zoom’s infrastructure, together with observing the transmission of assembly encryption keys by means of China.

Key Findings

  • The AES-128 keys, which we verified are adequate to decrypt Zoom packets intercepted in Web site visitors, seem like generated by Zoom servers, and in some circumstances, are delivered to members in a Zoom assembly by means of servers in China, even when all assembly members, and the Zoom subscriber’s firm, are exterior of China.
  • Zoom, a Silicon Valley-based firm, seems to personal three firms in China by means of which at least 700 staff are paid to develop Zoom’s software program. This association is ostensibly an effort at labor arbitrage: Zoom can keep away from paying US wages whereas promoting to US prospects, thus rising their revenue margin. Nevertheless, this association could make Zoom conscious of strain from Chinese language authorities.

1. Background: A US Firm with a Chinese language Coronary heart?

Zoom is a well-liked teleconference app whose reputation has elevated dramatically, given a lot of the world is underneath necessary work-from-home orders on account of the unfold of COVID-19. The app’s overarching design aim appears to be lowering friction in videoconferencing and making issues “just work.”

Determine 1: A image exhibits the Zoom brand above the title of one of Zoom’s Chinese language developer firms, “Ruanshi Software (Suzhou) Ltd.” (Source)

Whereas Zoom is headquartered in the United States, and listed on the NASDAQ, the mainline Zoom app seems to be developed by three firms in China, which all have the title 软视软件 (“Ruanshi Software”). Two of the three firms are owned by Zoom, whereas one is owned by an entity referred to as 美国云视频软件技术有限公司 (“American Cloud Video Software Technology Co., Ltd.”) Job postings for Ruanshi Software program in Suzhou embrace open positions for C++ coders, Android and iOS app builders, and testing engineers.

Zoom’s most recent SEC filing exhibits that the firm (by means of its Chinese language associates) employs at least 700 staff in China that work in “research and development.” The submitting additionally implies that 81% of Zoom’s income comes from North America. Operating growth out of China doubtless saves Zoom having to pay Silicon Valley salaries, lowering their bills and rising their revenue margin. Nevertheless, this association may additionally open up Zoom to strain from Chinese language authorities. Whereas the mainline Zoom app ( was reportedly blocked in China in November 2019, there are a number of third-party Chinese language firms that promote the Zoom app inside China (e.g.,,,

Any Characteristic You Like, As Lengthy As It’s Velocity

In the previous few years, a quantity of safety points concerning Zoom have come to gentle. These points have included unintentional bugs, resembling vulnerabilities in Zoom’s screen sharing feature, and privateness issues, resembling Zoom sharing data with Fb. Nevertheless, maybe the most distinguished safety points with Zoom encompass deliberate options designed to scale back friction in conferences, which additionally, by design, scale back privateness or safety. This consists of Zoom putting in a hidden web-server on Mac computer systems to avoid a Safari popup that customers needed to click on by means of earlier than they joined a Zoom assembly, a Zoom function that removes a password prompt throughout the set up course of (and as an alternative shows a deceptive password immediate later), a Zoom feature meant to permit Zoom customers at the similar firm (or ISP) to simply discover one another, and Zoom’s simple 9 or 10 digit code which is adequate to affix a gathering created with default settings, resulting in the well-reported phenomenon of “Zoom Bombing.”