A hybrid garbage-collection scheme combining time-based expiry (last-access timestamp cutoff), popularity-based retention, and editor-signed manifest exemptions forces adversaries conducting pollution or exhaustion attacks to continuously re-access or re-upload junk to prevent its deletion. A single honest editor's signature is sufficient to exempt important but infrequently accessed content from deletion indefinitely, while malicious editors cannot explicitly remove content from the system.

Content-oblivious replication delegates ongoing availability maintenance to 'manifest guarantors' — nodes holding content manifests — who periodically sample chunk replication factors and restore missing replicas without knowing the plaintext they protect, freeing the original publisher from any post-publication obligation. Two honest manifest holders (one content, one key) are sufficient to maintain replication with overwhelming probability even under adversarial conditions and high churn.

§3.3 defense

Simulation over erasure code parameters uniformly sampled from m∈[1,5] and n∈[5,500] shows that a 50-of-500 code is the best trade-off between overhead and robustness: it requires nearly 10× storage overhead to support 2^60 variable-size chunks and allows the network to tolerate more than 70% node failure before data is lost. Replication combined with erasure coding yields better durability than either strategy alone.

§4, Figure 2 evaluation

One-way indexing separates a published file into encrypted content blocks (indexed by hash1(block)), a content manifest (indexed by hash2(keyword)), and a key manifest (indexed by hash3(keyword)), so a storer holding all content chunks cannot recover the plaintext or keywords without inverting a cryptographic one-way function. Using distinct hash functions for each manifest type also minimizes the probability that a single node stores both manifests, preventing correlation.

§3.1 defense

In a 250-node PlanetLab deployment with 10–15% silent node failures and high churn, the median user retrieved a 20MB file in 65–85 seconds end-to-end (search + manifest download + chunk fetch + reconstruction + decryption). 15.12% of DHT lookups and 11.24% of maintenance operations failed; 20% of nodes accounted for 80% of failures, yet nodes with working connections completed lookups and maintained sufficient guarantors for manifest replication.

§4.1, Figure 3 evaluation

During the June 2025 shutdown, Iranian authorities blocked international One-Time Password (OTP) SMS delivery, preventing new sign-ins to foreign secure-messaging platforms and VPN services. This forced users toward government-approved domestic platforms that lack security and privacy protections. The blockade of OTPs effectively weaponized account-recovery flows as a secondary shutdown layer, disproportionately affecting users who needed to activate new circumvention tools during the crisis.

2025-iran-shutdown-measurement §Human Rights Implications port-blockingdpikeyword-filtering

Simple character-level perturbations (English) and homophone substitutions (Chinese), combined with LLM instruction-following prompts directing the model to use word substitutions in its output, successfully bypassed all input and output filters for all 41 input-blocked and 197 output-blocked queries across five major Chinese LLM services (Baidu-Chat, DeepSeek, Doubao, Kimi, Qwen). Every input-blocked query contained at least one keyword combination that alone triggered the filter, confirming keyword-matching rather than semantic classification.

2026-ablove-characterizing §VII-D keyword-filtering

Cross-national experiments conducted from Singapore, South Korea, and Taiwan during February 19–24, 2025 found no variance in blocking implementations, event syntax, or server infrastructure across all five Chinese LLM services. Input blocking was enacted identically in all three international locations, and services connected to the exact same server IP addresses globally — Kimi and Baidu-Chat connected to identical IPs and DeepSeek to the same two addresses across all tested locations.

2026-ablove-characterizing §VIII-A keyword-filtering

Input blocking in Chinese LLM services (DeepSeek, Qwen, Kimi, Doubao) is overwhelmingly consistent: all four services persistently block the exact same queries across all 5 measurement samples in both Simplified and Traditional Chinese. Output blocking is far less consistent, with only 29 out of 349 output-blocked queries blocked across all 5 samples. Baidu-Chat is exceptional: it performs almost no input blocking but instead relies heavily on post-search and output blocking (78.6% of blocks are output-phase).

2026-ablove-characterizing §VI-B keyword-filteringdpi

DeepSeek, Kimi, and Doubao all transmit analytics logs to the same Autonomous System (AS24429, Zhejiang Taobao Network Co., Ltd., a ByteDance/Volcengine subsidiary), with one monitoring endpoint IP directly overlapping between DeepSeek and Doubao. Additionally, all four non-Qwen services maintain connections with servers physically located in China throughout the chat session, transmitting user IDs, session IDs, viewport data, language preferences, and in Baidu-Chat's case, the full query text via URL-encoded CAPTCHA requests.

2026-ablove-characterizing §VI-D keyword-filtering

All five Chinese LLM services transmit partial or complete responses to the client machine even when output blocking is triggered, representing a major information leak. For DeepSeek and Qwen, truncated blocked responses are on average close in token length to full successful responses. For Baidu-Chat, the complete response is transmitted to the client but only partially rendered in the browser UI, with only a word or two visible on screen.

2026-ablove-characterizing §VI-C keyword-filtering