Washington ( CNN ) -- U.S. intelligence now believes Edward Snowden did not gain access to the `` crown jewels '' of National Security Agency programs that secretly intercept and monitor conversations around the world , CNN has learned . The Obama administration is reviewing what the admitted leaker of classified information actually got his hands on and what damage he may have caused . The ongoing damage assessment indicates he did not gain access to what is called ECI or `` extremely compartmentalized information , '' according to a U.S. official familiar with the review . Snowden fled to Moscow after his leaks in June and has been stranded at the Moscow airport awaiting a response to his request for temporary asylum . He faces espionage charges in the United States . With Snowden still at large and the publication of agency surveillance secrets publicized , the intelligence community may have good reason to downplay the impact of what he has revealed . However , the official said the intelligence community remains adamant that Snowden caused serious damage . The administration believes it knows the extent of the material that was downloaded . `` We are not downplaying it , '' the official said , explaining that assessing the matter over weeks has enabled authorities to focus more directly on the impact of Snowden 's actions . Court renews secret U.S. surveillance program . The official spoke to CNN on background because the assessment is not fully completed . CNN can not independently verify the statements made either by the administration or Snowden . Officials do not dispute that Snowden had critical information about how NSA programs worked . `` But just because you have the blueprints does n't mean you have the manual , '' the official said . A key question is whether Snowden , a former NSA contractor , really knows how the programs work at a detailed technical level . Snowden did leak sensitive documents about anti-terror programs , detailing secret telephone metadata and e-mail surveillance . U.S. officials have said that terror groups are aware of the Snowden leaks and are responding internally , like adjusting communications and security . NSA Director Keith Alexander said last week the United States has concrete proof terrorists are making changes and taking actions that are going to `` make our job harder . '' Other officials are less resolute about the extent of the exposure . The top lawyer for the Office of the Director of National Intelligence said it is not clear how much U.S. adversaries will adjust based on what is known already . Ex-CIA chief : What Snowden did . `` It 's too early to tell yet whether it is going to have an impact , but there 's no question that they have sat up and taken notice of specifically what has been released here and the impact it has on their communications , '' Robert Litt , general counsel for the national intelligence office said last Friday . The assessment also has concluded that Snowden took advantage of knowing that a good deal of information was concentrated in one portion of the NSA 's computer system . `` What he had was information that was centralized so it could be shared broadly , '' the official said . This is similar to the assessment reached in the case of Army Pvt . Bradley Manning where information was stored in ways that large numbers of personnel could access it under certain circumstances . Manning is accused of leaking documents to WikiLeaks in the largest case of its kind in U.S. history . He is currently on trial before a military court . Deputy Defense Secretary Ashton Carter said last week that Snowden exploited a weakness that came from a desire to make the information more accessible to those in the intelligence community . `` In an effort for those in the intelligence community to be able to share information with one another , there was an enormous amount of information concentrated in one place , '' Carter said during a panel at the Aspen Security Forum . `` It creates too much information in one place . '' As such , the government has accelerated efforts to better secure classified information , improvements that had begun even before Snowden went public . The government believes Snowden was aware that upgrades were being made to NSA systems tagging data and users so that downloads were recorded , but Snowden accessed portions where that work had not been completed . In addition , system administrators like Snowden and others will be subject to more stringent rules . Downloads will require a second more senior employee to `` watch , log and observe '' what material is being accessed the official said . Access codes and passwords also have been changed .
Edward Snowden admittedly leaked classified information on surveillance programs to media . Comment: The intelligence community adamant Snowden caused serious damage , official says . Assessment also finds Snowden knew a good deal of information was in one place .