SCREECHNET
The internet, over a phone call. Literally.
Your laptop is the modem. Your phone on speaker is the line.
How to go online like it's 1995
- Call a friend. Any phone call. Put it on speaker.
- Both open this page and flip POWER. Allow the microphone.
- Lay the phone next to your laptop and turn the volume up.
- Type, hit TRANSMIT. Your message screeches down the line and types itself out on their screen.
Alone? Tick LOCAL ECHO and your own mic decodes what your speakers send.
Built for real phone calls. Calls are hostile to modems: codecs drop packets, jitter buffers stretch time and noise cancellation eats steady tones. So SCREECHNET hops between 16 tones and carries error correction. If a piece is lost anyway, you get ░░░ in its place instead of losing the whole message. It also helps to turn off noise cancellation or "voice isolation" on the call.
Private line. Agree on a room key with your friend and both type it in. What leaves your speakers is then AES-GCM ciphertext: anyone listening to the call hears the screech but reads nothing. Read the 3-part key ID (e.g. 3F-A9-C2) to each other to confirm you typed the same key. Don't say the key itself on the call. Your browser derives the key with PBKDF2 (600k rounds), and the key never leaves your device. Use a long passphrase: whoever records the call can try to guess it offline.
How it works: Like modern ham-radio modes such as FT8 and Olivia. The signal is 16-tone MFSK at 25 symbols per second, with a Costas array for sync, a K=7 convolutional code with soft Viterbi decoding, bit interleaving, and a re-sync marker plus CRC-16 on every 8-byte block. No server is involved. The only network is the phone call.