The suspected Chinese surveillance nodes are hosted in data centers that explicitly prohibit 'circumvention services' (proxy/VPN services) in their terms of service, yet the nodes operate safely for extended periods. This suggests the operators benefit from either state-sanctioned access or ISP-level protection from ToS enforcement, consistent with a government or contractor intelligence-collection operation.

A community scan of the I2P network database (netDb) in July 2026 identified a cluster of suspicious router nodes uniformly running I2P version 0.9.66 (three versions behind the current 0.9.69), all hosted in Chinese domestic data centers rather than residential broadband. The nodes exhibit anomalous uniformity in their router capabilities (Caps) configuration and self-reported versions, a pattern inconsistent with organic user deployments.

Issue body detection

The suspicious Chinese I2P nodes rotate their IP addresses regularly and simultaneously as a coordinated group, and some of the observed IPs have prior history of malicious behavior (SSH brute-forcing, remote exploitation) in threat-intelligence databases. Simultaneous coordinated IP rotation distinguishes state-run infrastructure from organic users and is a fingerprint of centrally managed probe fleets.

Issue body detection

The author released a netDb scanner tool that reads the local I2Pd network database, identifies routers hosted on Chinese IP ranges, and exports results as IP lists for firewall rules. The tool supports filtering by country (--cn-only), JSON export, and IP-list export, enabling operators to block suspected surveillance nodes at the OS firewall layer before any I2P connection is made.

Issue body — scanner download defense

The blog author, drawing on evaluation experience, concludes that LetsVPN's failure was not caused by IP exhaustion or ordinary node instability but by precise protocol-signature identification: once the GFW extracts a client handshake feature, it can simultaneously block all connections sharing that signature across hundreds of thousands of users.

2026-anon-letsvpn-vpn §公告里的几句大实话 dpitls-fingerprintactive-probing

All sampled popular-service prefixes contain at least two TLS-authenticated witnesses, and more than half contain 35 or more witnesses; by contrast, only 40% of randomly selected prefixes feature any valid witnesses. CT log analysis across 5 months shows that witnesses span just 17.4% of the routable IPv4 space, confirming that witness coverage concentrates on professionally-hosted infrastructure.

2026-doumanidis-howlr-client-driven-approach §4 bgp-hijackactive-probing

CensorLess's function refresher automatically retires serverless bridges and deploys fresh ones in batches across diverse regions; the expected time until a bridge is identified and blocked in practice is 2 days (per Fifield et al.), while Tor bridges in China are discovered within 2–36 days. The old bridge is only removed after all clients have completed live migration to a new URL, maintaining uninterrupted connectivity.

2026-kang-censorless-serverless §4.5 active-probingip-blocking

CensorLess's threat model explicitly relies on a rational-censor assumption: the censor will not block entire cloud-provider IP ranges or domain namespaces because the collateral damage to legitimate business services would be politically and economically unacceptable. AWS Lambda's inherent IP-address ephemerality (new IPs on each invocation, function lifetime up to 15 minutes) means even censors willing to attempt enumeration face a continuously shifting target distributed across the cloud provider's global address space.

2026-kang-censorless-serverless §4.2 ip-blockingasn-blackholingactive-probing

FlowPaint evades all three GFW-style rule-based middlebox configurations — stateful TCP keyword reassembler (Censor A), heuristic header filter dropping flows with TCP data offset ≥ 9 (Censor B), and anti-replay validator caching (SEQ, payload_hash) pairs and injecting bidirectional RSTs on replay detection (Censor C). Geneva's duplicate-packet desynchronization strategy fails against Censor C because its malformed artifacts simultaneously satisfy the anti-replay blocking condition, while FlowPaint succeeds by recalculating checksums and injecting no extra packets.

2026-ling-one-prompt-censorship-evasion §5.2, Table 4 dpirst-injectionactive-probing

Address blocking is a losing strategy for the censor: with n=8 endpoints and µ/λa = 1 (discovery as fast as rotation), address-denial probability falls below 10^-2, and even when the censor discovers twice as fast as the defender rotates (µ/λa = 0.5), 7 endpoints keep address denial below 10^-2 (Lemma 1, Figure 1). The collateral budget γ means the censor cannot even block all addresses it discovers, and Corollary 1 gives the explicit threshold: n ≥ ln(1/ε) / ln((λa+µ)/λa) endpoints suffice for any target ε.

2026-maiti-block-a-mole-sustainability-frontier §5, §8.1, §8.10, Lemma 1, Corollary 1, Figure 1 ip-blockingactive-probing