The FBI has appealed for a second time to the US Senate to retain some form of control over high level encryption products.
The Bureau believes the government should retain the keys to access such products, to help law enforcement agencies combat criminals and terrorists.
Speaking to a Senate technology panel on Wednesday the agency's director, Louis Freeh, said law enforcement agencies were unanimous that, without such controls, criminals would be able to evade existing methods of tracking and surveillance.
However, he accepted that a full key recovery system was probably not possible, given secrecy concerns and the availability of encryption products from overseas, but hoped some kind of voluntary key recovery system might be put in place.
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