Apple's new iPhone 6, released this month, and Google's coming update of the Android smartphone have data encryption so sophisticated that only the user may unlock it. Even law enforcement officers with search warrants would not have access.
               
"It is fully possible to permit law enforcement to do its job while still adequately protecting personal privacy," Holder said in a speech before the Global Alliance Against Child Sexual Abuse Online.
               
Holder said quick access to phone data can help law enforcement officers find and protect victims, such as those targeted by kidnappers and sexual predators.
               
Justice Department officials said Holder is merely asking for cooperation from the companies at this time.
               
Holder's comments echo concerns raised last week by FBI Director James Comey.
               
"What concerns me about this is companies marketing something expressly to allow people to place themselves beyond the law," he said.
 
Comey said agents at the FBI have had conversations with Apple and Google to better understand the technology.