Mandatory National ISP-Level Internet Filtering: Mark Newton sends a letter

Mark Newton has published yet another letter to his Federal Labor MP Kate Ellis and it is well worth reading.

Excerpt from PDF copy of the letter dated 20 December 2009:

EVIDENCE-BASED POLICY FORMULATION

For the year that it has taken to conduct his six-week trial, the Minister has claimed that evidence gained from the trial will inform the policy.

The Minister also relied on evidence supplied by Mr. Tom Woods in 2007 as a justification for moving from user-based filtering (under the Coalition's policy) to ISP-based censorship due to Mr. Woods' ease of bypassing the Coalition's NetAlert filters.

So it's curious that the evidence5 delivered by Enex Testlab in the trial results released on 15 December weren't similarly persuasive.

Enex found that all of the solutions they tested could be trivially bypassed when blocking defined blacklist

(with success rates for circumvention blocking ranging from 16.2% down to a lousy 8.1%).

The success rates were higher when additional censorship methods were employed, but even then none of the products successfully prevented circumvention and all of them experienced reduced reliability.

Specially notable is that WebShield, the ISP in Australia with the most experience at running censorship systems, was included in the testing and was circumvented.

Even the experts can't prevent bypass, leaving the efficacy of these systems worse than the PC-based filtering systems employed by the previous Government.

At least a PC system can intercept your Google search to block knowledge of bypass methods.

ISP systems have no such defensive capability.

Other results of the trial include further confirmation that increases in accuracy lead to decreases in performance (You can have it fast or good - Pick one) and a moderate increase in underblocking errors as measured against the 2007 lab trial previously carried out by Enex Testlab for ACMA.

5 http://www.dbcde.gov.au/online_safety_and_security/cybersafety_plan/
internet_service_provider_isp_filtering/isp_filtering_live_pilot"

Report into the conduct of the trial. Recommendation is to ignore the Minister's press release and examine the raw data in the Enex report.