This page is served by an unhackable 14 KB x86-64 operating system.
$200 Bitcoin bounty — until 2027-02-12.
This server’s TLS private key is also the private key of
bc1qca8d90v433p5wuq50mqflvvnwxyj63fse8w447.
Hack the server, read the key, and take the money. Moving the coins is the proof.
Verify against the live TLS handshake (zero-knowledge cross-curve proof):
python3 tools/bounty.py --verify 15kb.org
k15 turns a folder of static files into a bootable x86-64 HTTPS image: boot sector, virtio-net, ARP, TCP, TLS 1.3 and HTTP in 13,859 bytes of assembly, with the files behind it. There is no Linux on the disk, no kernel, no shell, no file system, no login, and no executable data pages; any CPU fault resets the machine back into k15.
| on this 2-vCPU cloud server | k15 | nginx + OpenSSL |
|---|---|---|
| new TLS 1.3 connections / s | 7,500 to 9,000 | 2,100 to 2,200 |
| small pages / s, connections kept | 105,000 to 125,000 | 30,000 to 34,000 |
| files of 14 KB / s | 30,000 to 35,000 | 24,000 to 27,000 |
| a 1.5 MiB file | 1.2 GB/s | 0.90 to 0.98 GB/s |
| memory per held TLS connection | 128 bytes | 25.8 KiB |
TLS 1.3 only (X25519, ECDSA P-256, AES-128-GCM; SSL Labs: A), GET and HEAD only. Changing a file or certificate means booting a new image (4 seconds).
Source, proof and benchmarks (bench/README.md): github.com/FileSherlock/k15.