WASHINGTON — The keepers of a Nazi archive have delivered copies of Gestapo papers and concentration camp records to museums in Washington and Jerusalem, providing Holocaust survivors a paper trail of their own persecution.

Six computer hard drives bearing electronic images of 20 million pages arrived late Monday at the U.S. Holocaust Memorial Museum in Washington and at the Yad Vashem Martyrs' and Heroes' Remembrance Authority in Jerusalem.

Last week, the director of the International Tracing Service, custodian of the unique collection that has been locked away for a half century in Germany, released the files for transfer to the two museums.

But it will be months before the archive can be used by survivors or victims' relatives to search family histories. Even after it opens to the public, navigating the vast files for specific names will be nearly impossible without a trained guide.

"Over the years, Yad Vashem has amassed a great deal of experience and knowledge in digitizing archival information and making it user friendly," Avner Shalev, chairman of Yad Vashem, said in a statement Tuesday. "However, the material received last night is complex and vast, taken from a number of camps, which is organized in complicated and varying ways. We expect it will take a lot of resources to sift through the material and catalog it."

The hard drives contain the first tranche of digital copies from one of the world's largest Nazi archives, with the final documents scheduled to be copied and delivered by early 2009.

"This first transfer is the beginning of a major undertaking," said the Washington museum's director, Sara J. Bloomfield, in a statement Tuesday. "Our goal is to help survivors."

The museums now face a complex task of organizing the material on the hard drives, which is so vast, it will take days to transfer to museum computers, according to Paul Shapiro, director of the museum's Center for Advanced Holocaust Studies.

The museum has been training researchers to work with the documents. An index of about 17.5 million names on file with ITS is the key to finding documents and will arrive this year. The index has been scanned from about 50 million cards in varying formats, organizational systems and even scripts.

Most documents in the archive are written by hand, sometimes in old German script. They also contain variations in the spelling of names, many of which are recorded phonetically. That makes it impossible, for now, to convert large numbers of files to a digitally searchable form.

"You can't Google them," Shapiro says. "The question is, how do we get people what they want?"

One tool the museum is preparing is a search engine it plans to make accessible soon on the Internet. It will allow people to search through a separate, limited index of the archive and get a sense of what kind of documents exist. That index describes tranches of the documents, where they came from and where they are stored. It could provide clues about whether the information users are seeking might be there.