Signal President Meredith Whitaker explained the encrypted messaging app's reliance on Big Tech's infrastructure after a major Amazon Web Services (AWS) outage last week disrupted Signal's service. Despite Musk's criticism, Whitaker believes Signal has no other options.

After an AWS outage disrupted Signal's service, Musk was quick to criticize the encrypted messaging app's reliance on big tech companies. But Whitaker responded by posting on Bluesky that the problem is not that Signal "chooses" to run on AWS, but that the power in the infrastructure field is too concentrated, resulting in "there is actually no other choice: the entire technology stack is basically controlled by 3-4 companies."

Whitaker said the fact that many people don't know Signal uses AWS is "concerning" because it shows they don't understand how concentrated the cloud infrastructure industry is. She emphasized that the question should not be "Why Signal uses AWS?" but rather look at the infrastructure requirements of any global real-time large-scale communications platform and think about why there is no realistic alternative to AWS and other hyperscale cloud service providers.

Whitaker pointed out that AWS, Microsoft Azure and Google cloud services are the only viable options for Signal to provide reliable services on a global scale without spending billions of dollars to build its own infrastructure. "Running a low-latency instant messaging platform capable of hosting millions of concurrent audio/video calls requires a pre-built, global compute, storage and edge network that requires ongoing maintenance, large amounts of power, and constant attention and monitoring," she explained.

Whitaker added that Signal only "partially" runs on AWS and uses encryption to ensure that neither Signal nor AWS can view the content of users' conversations. This AWS failure has a wide range of impacts. In addition to Signal, it also caused service interruptions such as Starbucks, Epic game store, Ring doorbell, Snapchat, Alexa devices and even smart beds.

"My hope is that the AWS outage becomes a learning moment and makes the risks of concentrating our world's nervous system in the hands of a few companies very clear," Whitaker said. She used the outage to highlight the problem of "concentration of power" in the cloud infrastructure industry, calling attention to the potential risks posed by this monopoly.

This incident once again highlights the heavy reliance of modern Internet services on a few large cloud service providers, and the systemic risks that this dependence may bring.