Authorities are likely to confront growing number of encrypted devices.

The use of court-approved wiretaps in domestic criminal cases in 2013 increased five percent from the year before, and authorities largely defeated encryption methods on the mobile, landline, and other devices they tapped, according to a report Wednesday from the US agency that oversees the country's court system.

The Administrative Office of the United States Courts, using the latest available figures, said there were 3,576 wiretaps reported. That represented a nine-percent bump in federal court orders and a three percent increase from state judges. The report said that only one wiretap application was denied for all of 2013.

When it comes to cracking encryption, the authorities said they encountered encryption 41 times, up from 15 the year before.

"In nine of these wiretaps, officials were unable to decipher the plain text of the messages. Encryption was also reported for 52 state wiretaps that were conducted during previous years, but reported to the AO for the first time in 2013. Officials were able to decipher the plain text of the communications in all 52 intercepts," the report said.

The figures do not include secret orders from the Foreign Intelligence Surveillance Court.

Last year's wiretap report for 2012 was the first time the authorities had ever noted that a wiretap was foiled or encountered encryption.

The authorities are likely to be confronted with an ever-growing number of encrypted devices thanks to Edward Snowden's National Security Agency spying revelations. The Snowden leaks have prompted a cottage industry of sorts in which developers are producing and searching for ways to scramble communications in a bid to defeat the NSA's spying tactics, which a White House panel on Wednesday concluded were legal.

Meanwhile, Wednesday's congressionally mandated wiretap study said that of all the wiretaps, 93 percent, or 2,158 of them, dealt with telephones, "the majority of them involving cellular telephones."

very high number of intercepts