AMERICAN CIVIL LIBERTIES UNION WASHINGTON OFFICE 122 Maryland Avenue, NE November 1, 1985 Washington, DC 20002 -------------------- National Headquarters Mr. David Chaum 132 West 43rd Street Centre for Mathematics and Computer Science New York. NY 10036 P.O. Box 4079 (212) 944-9800 19O9 AB Amsterdam Norman Dorsen President Dear Mr. Chaum: Ira Glasser Executive Director Eleanor Holmes Norton CHAIR National Advisory Council Thank you for sending me a most interesting article. A society of individuals and organizations that would expend the time and resources to use a series of 'digital pseudonyms' to avoid data linkage does not in my opinion make big brother obsolete but acts on the assumption that big brother is ever present. I view your system as a form of societal paranoia. As a matter of principle, we are working to enact formal legal protections for individual privacy rather than relying on technical solutions. We want to assume a society of law which respects legal limits rather than a society that will disobey the law, requiring citizens to depend on technical solutions. e.g. require a judical warrant for government interception of data communications rather than encrypt all messages on the assumption that regardless of the lawt the government will abuse its power and invade privacy. As a matter of practicality, I do not think your system offers much hope for privacy. First, the trend toward universal identifiers is as much a movement generated by government or industry's desire to keep track of all citizens as it is by citizens seeking simplicity and convenience in all transactions. At best, your system would benefit the sophisticated and most would opt for simplicity. The poor and the undereducated would never use or benefit from it. Finally where there's a will, there's a way. If government wants to link data bases, it will, by law, require the disclosure of various individual pseudonyms used by citizens or prohibit it for data bases which the government wants to link. Since corporations make money by trading commercial lists with one another, they will never adopt the system or if it is adopted, will use "fine printn contracts to permit selling various codes used by their customers to other firms. The solution remains law, policy, and consensus about limits on government or corporate intrusion into areas of individual autonomy. Technique can be used to enforce that consensus or to override it. It cannot be used as a substitute for such consensus. Sincerely Yours, /Sig/ Jerry J. Berman Chief Legislative Counsel & Direrector ACLU Privacy Technology Project cc: John Shattuck