Modern cellular networks are built to serve millions upon millions of users, all while maintaining strict encryption across all communications. But earlier cellular networks were by no means so secure, as [Nostalgia for Simplicity] demonstrates in a recent video.

The video begins with an anecdote — our narrator remembers a family member who could listen in on other’s conversations on the analog AMPS phone network. This was easily achieved simply by entering a code that would put an Ericsson handset into a test mode, in which it could be switched to tune in any desired AMPS channel. Since the communications were transmitted in a purely analog manner, with no encryption of any sort, any conversation on such a network was basically entirely open for anyone to hear. The video shows a recreation of this method, using a software-defined radio to spin up a low-power, very local AMPS network. A phone call is carried out between two handsets, with a third handset able to listen in just by using the special test mode.

If you’re particularly keen to build your own first-generation AMPS phone network, just know that it’s not really allowed due to rules around spectrum allocations. Still, it’s entirely possible as we’ve covered before. It doesn’t even take much hardware in our modern SDR era.

Bitcoin Magazine

El Salvador’s AuthenticDoc Goes Live: Bitcoin-Powered Signatures Eye $60B DocuSign

AuthenticDoc, a decentralized digital signature platform developed in El Salvador, launched on November 13, 2025, at the Adopting Bitcoin conference in San Salvador. The tool uses the Nostr protocol for its open-source, decentralized architecture, incorporating Bitcoin-compatible cryptography to enable tamper-proof document verification and user-controlled private keys.

Co-founder Fabian, of the Salvadoran firm illuminodes, announced the release during the conference. “The digital signature landscape is ripe for innovation, and AuthenticDoc is leading the charge,” Fabian said. “We’ve harnessed the power of decentralized open protocol technology to deliver unparalleled security and control, effectively eliminating single points of failure that plague traditional solutions. Our platform provides a robust, tamper-proof cryptographic verification and authentication solution that businesses can trust, all while making it accessible and affordable.”

Built by Bitcoiners, the start-up addresses vulnerabilities in centralized platforms like DocuSign, which holds about 70% of the $10 billion digital signature market. According to their press release, the sector is projected to grow to $60 billion by 2030 at a 40% compound annual growth rate, fueled by regulations such as the EU’s eIDAS and the U.S. ESIGN Act, alongside remote work trends and AI-driven authenticity challenges.

The platform’s core features include trustless identity verification, private key management for users, and ISO-standard compliance for enterprise use. It eliminates reliance on centralized storage by using Nostr’s event-based system, where documents and signatures are cryptographically signed and distributed across a network of relays, ensuring robust data storage and distribution.

Diego, head of technology at illuminodes, emphasized the shift from legacy systems. “Our decentralized architecture empowers users with private key control and trustless identity verification, moving beyond the vulnerabilities of centralized systems,” Adding that, “this is not just an incremental improvement; it’s a paradigm shift in how digital signatures are secured and managed.”

AuthenticDoc is free for basic use, with paid tiers based on volume for enterprises, undercutting competitors’ license-based models. The platform supports global expansion from its El Salvador headquarters, leveraging local talent and regulatory support to target markets in Latin America, North America, and Europe.

This post El Salvador’s AuthenticDoc Goes Live: Bitcoin-Powered Signatures Eye $60B DocuSign first appeared on Bitcoin Magazine and is written by Juan Galt.