Root by DID: SSH with no ports, no passwords, and a signed receipt — the XionIA demo

XIONIA · TECHNICAL LOG

Root by DID: SSH with no ports, no passwords, and a signed receipt — the XionIA demo

276 seconds of root shell over a direct P2P tunnel. The key was born with the session and died with it. Six Ed25519-signed records — including the failed attempts.

11 · 06 · 2026≈ 6 min readFernando López (Mamanga)

tldr — xionia console

$ tldr

Today we opened a root SSH session on a remote host without opening a port, without a password, and with no .pem to steal. Identity was a DID (an Ed25519 keypair, not a user account). Transport was the end-to-end encrypted session that already existed between the two nodes. Authorization was explicit: the host's owner enabled our DID in a signed catalog — and revoked it afterwards, with the rejection itself leaving a receipt. The session lasted 4m36s, moved 61.6 KB, and when it closed nothing was left behind. The entire episode — successful session, two failed attempts, one administrative rejection — was recorded and signed: 6 records, every signature verifiable.

0ports opened to the internet

4m36sof real root shell, egress verified

61.6 KBaccounting mirrored on both nodes

6/6Ed25519 records verified, failures included

01The lesson the largest theft in history wrote down

A week ago we dissected the US$6.36 billion Binance theft: no cryptographic primitive failed — the trust model did. The authority to move billions sat one hop from a laptop, identity was network position, and the legitimate signatures were the weapon. Four principles were written in fire: identity is not network position, zero one-hop signing routes, discovery must not be authority, and hosts are potentially hostile.

This post is the other half of that conversation: what it looks like when those principles are taken seriously in host administration. Spoiler: one command, three gates, and a signed receipt.

02What was built: three gates, zero paraphernalia

XionIA runs a P2P kernel with sovereign DID identity, end-to-end Noise transport, and NAT traversal that opens no ports. The new remote command builds the missing layer on top: a real administrative shell into another host — stock OpenSSH, unpatched, with the kernel's identity and authorization.

What did NOT survive the design

• Ports: the session sshd listens on no interface (it serves one connection over stdin/stdout, wired to the tunnel)
• Passwords and .pem files: the Ed25519 key is generated in memory and dies with the session — nothing to steal afterwards
• Relays: the administrative session rides only the direct channel between the two kernels, never a third party
• Authorization inherited from the network: being "inside" gets you nothing

What is there instead

• Gate 1 · Node ACL — who may talk (the same list as chat)
• Gate 2 · ROOT_ADMIN catalog — who may touch the host: off by default, DID-by-DID, signed by the owner
• Gate 3 · Ephemeral key — for how long: a new key per session, dead with the session
• An Ed25519 receipt for every session and every attempt — rejections included

03The demo, with real numbers

Two real nodes: a linux/amd64 console and an ARM board (a Raspberry Pi on Arch), each with its DID, both behind home networks, introduced by the project's beacon and connected directly.

demo — 2026-11-06 · two real nodes

# on the target host, the owner enables — nothing works without this:

$ remote allow xeon

✅ ROOT_ADMIN enabled for xeon — catalog re-signed

# on the initiator (an unprivileged user, nothing more):

$ remote jubilarte root

🕳 opening SSH tunnel to jubilarte (direct only, never relay)...

✅ Tunnel ready — the remote node ran its session openssh (local port 35563).

Ephemeral key SHA256:Gkb1gmbD… · session host SHA256:fcAVmc9H…

# and inside:

[root@alarm ~]# whoami

root

[root@alarm ~]# curl ifconfig.me ← real egress via the normal route

190.220.45.26

exit closed the session, the tunnel, and the key — all together. What both ends logged:

Root sessioninteractive shell, 276 seconds4m36s

Tunnel trafficaccounting mirrored on both nodes61.6 KB

Ephemeral keysa new one per session — three sessions, three distinct keys3/3

Orphan processes and leftoversthe session directory vanishes on close0

Ed25519-signed recordssuccessful session + 2 failed attempts + 1 administrative rejection6/6 ✔

And the part almost no product can show: the failures left receipts too. Two earlier attempts were recorded in the signed log with their duration (0 s), their traffic (~3 KB of handshake), and each attempt's key fingerprint. After the authorization was revoked, a retry was rejected (NOT_ADMIN) with a 0-byte tunnel — and that rejection was signed too. No session and no attempt goes unrecorded.

04Audit without curiosity

Noise outside, SSH inside. The target node's kernel bridges already-encrypted bytes: it can sign the receipt — which DID came in, when, how much traffic — without being able to read the session's content.

Metadata is audited; content is not exposed to the auditor. That double wall is the difference between a log a compliance officer signs off and a promise a compliance officer distrusts. And the accounting closes on both ends: the 61.6 KB are signed by the node that entered and by the node that received, mirrored.

05What this is NOT (honesty up front)

LIMIT 01It is not a VPN

Arbitrary ip:port tunneling is prohibited by design. Reaching other machines on the node's LAN will happen only through authorized aliases, without revealing IPs.

LIMIT 02One scenario proven

The published test covers two real nodes with a direct path. Restrictive double-NAT on both sides is next in the project's field-test queue.

LIMIT 03All-or-nothing for now

ROOT_ADMIN enables the full host layer, DID by DID. Granularity (jail / host / bastion by alias) is the catalog's next rung.

LIMIT 04No replacement for custody, HSMs, or MPC

It is the authenticated-communication and verifiable-authorization layer — the bottleneck the Binance theft exposed, not the vault.

06Closing

Traditional administrative access carries decades of debt: reused passwords, .pem files in repositories, exposed IPs, jump hosts whose security is an outdated VPN client. The alternative demonstrated today asks for no credentials: it asks for identity. The owner authorizes a DID, the session lives and dies with its key, and the whole episode is signed — rejections included.

The VPN gives them the whole network; this gives you the exact arm, with a signed receipt.

xionia.uk — project hub

Fernando López (Mamanga) — XionIA Project, Corrientes, Argentina.

Data: transcript of the project's internal test of 2026-11-06 between two real nodes (captura-test.txt), xionia-kernel v9.2. On the Binance theft: on-chain analysis by TRM Labs and public confirmations (2026-10-29/31).