Tag Archives: forensic

Full Disk Imaging is Expensive Overkill for eDiscovery Collection

Early in my tenure as co-founder at Guidance Software (EnCase), we commercialized full-disk imaging circa 2001 with EnCase Forensic edition, which was the first Windows-based computer forensics tool. EnCase Forensic enabled broader market adaption of computer forensic drive imaging, but the tool was originally designed for law enforcement to perform criminal computer evidence seizures. We were thinking more CSI than ESI.

However, soon a funny thing happened. For a two to three year period in the mid-2000s, a majority of standalone forensic software purchases came from eDiscovery service providers. Law enforcement represented a sizable minority during this “surge period” of commercial sector purchases, but we eventually realized that the eDiscovery services community was in the process of standardizing on full disk imaging as their default collection practice.

I have a few theories on why this trend occurred, but suffice to say that one of the many reasons that full-disk imaging is burdensome is because the process often involves service providers traveling out to the individual custodians, which is very disruptive to employees, not to mention time consuming. Additionally, as eDiscovery processing and hosting fees are usually calculated on a per-gigabyte basis, costs are increased exponentially. In a word, this is overkill, with much more effective and efficient options now available.

However, many eDiscovery practitioners continue to collect or direct the collection of Electronically Stored Information (ESI) through full disk forensic “images” of targeted media as a routine practice. Full disk images capture every bit and byte on a hard drive, including system and application files, unallocated space and a host of irrelevant user-created data. While full disk images may be warranted in some limited situations, the expense and burden associated with the practice can be quite extensive, particularly in matters that involve multiple custodians.

The Duty to Preserve Only Extends to Relevant Information

It is established law that the duty to preserve evidence, including ESI, extends only to relevant information. Hynix Semiconductor Inc. v. Rambus Inc., 2006 WL 565893 (N.D.Cal. Jan. 5, 2006) at *27. (“The duty to preserve evidence, once it attaches, does not extend beyond evidence that is relevant and material to the claims at issue in the litigation.”)  As noted by the Zubulake court, “Clearly [there is no duty to] preserve every shred of paper, every e-mail or electronic document, and every backup tape…Such a rule would cripple large corporations.”  Zubulake v. UBS Warburg LLC, 220 F.R.D. 212, 217 (S.D.N.Y. 2004) (“Zubulake IV”).

The vast majority of ESI on a full disk image will typically constitute irrelevant information. As stated by one court, “imaging a hard drive results in the production of massive amounts of irrelevant, and perhaps privileged, information.” Deipenhorst v. City of Battle Creek, 2006 WL 1851243 (W.D.Mich. June 30, 2006) at *3.  In noting that the “imaging of computer hard drives is an expensive process, and adds to the burden of litigation for both parties,” the Deipenhorst court declined to require the production of  full disk images absent a strong showing of good cause. See also, Fasteners for Retail, Inc. v. DeJohn et al., No 1000333 (Ct. App.Ohio April 24, 2014).

Similarly, in Zubulake v. UBS Warburg LLC, 2004 WL 1620866 at *8 (S.D.N.Y. July 20, 2004) (“Zubulake V”), Judge Scheindlin suggested that eDiscovery could be more manageable for producing parties but still defensible by taking advantage of the development of technology like X1 Distributed Discovery, which would be capable of conducting distributed keyword searches.  She anticipated that, due to the expansion of eDiscovery in coming years, counsel “must be more creative” because:

[It may not always] be feasible for counsel to speak with every key player, given the size of a company or the scope of the lawsuit, counsel must be more creative. It may be possible to run a system-wide keyword search; counsel could then preserve a copy of each “hit.” [FN75] Although this sounds burdensome, it need not be. Counsel does not have to review these documents, only see that they are retained. For example, counsel could create a broad list of search terms, run a search for a limited time frame, and then segregate responsive documents. . .

FN75. It might be advisable to solicit a list of search terms from the opposing party for this purpose, so that it could not later complain about which terms were used.

The recommended collection and preservation approach described by Judge Scheindlin is a far cry from obtaining full-disk images of the hard drives of each potential custodian, and in fact maps directly to the capabilities of X1 Distributed Discovery.

Courts do require that ESI be collected in a forensically sound manner, which does not mean a full forensic disk image is required, but generally does entail that metadata is not altered and a documented chain of custody is maintained. Historically, eDiscovery collection efforts not involving full disk imaging would often result in the loss or alternation of metadata. More advanced enterprise class technology, such as X1 Distributed Discovery, can accomplish system-wide searches that are narrowly tailored to collect only potentially relevant information while preserving metadata at the same time. This process is better, faster and dramatically less expensive than manual disk imaging. As with the Zubulake V decision, which advocates employing technology to perform “system-wide keyword searches”, courts recognize that advanced computer software can be deployed to limit the scope of computer searches and thus support reasonable discovery efforts.

With X1 Distributed Discovery (X1DD), parties can perform targeted search collection of the ESI of thousands of endpoints over the internal network without disrupting operations. The search results are returned in minutes, not weeks, and thus can be highly granular and iterative, based upon multiple keywords, date ranges, file types, or other parameters. This approach typically reduces the eDiscovery collection and processing costs by at least one order of magnitude (90%). This method is sound from an evidentiary standpoint as the collected data is preserved in its native file format with its metadata intact. X1DD features a solid chain of custody and robust logging, tracking and reporting.

The authorities cited above establish that effective technology can enable corporate counsel to establish a highly defensible process that at the same time minimizes cost. Routine full-disk imaging, over collection, and high eDiscovery costs are symptoms of an absence of a systemized process.  By establishing a scalable and system-wide eDiscovery process based upon the latest technology, large organizations can save millions while improving compliance.

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Authenticating Internet Web Pages as Evidence: a New Approach

By John Patzakis and Brent Botta

In recent posts, we have addressed the issue of evidentiary authentication of social media data. (See previous entries here and here). General Internet site data available through standard web browsing, instead of social media data provided by APIs or user credentials, presents slightly different but just as compelling challenges.

The Internet provides torrential amounts of evidence potentially relevant to litigation matters, with courts routinely facing proffers of data preserved from various websites. This evidence must be authenticated in all cases, and the authentication standard is no different for website data or chat room evidence than for any other. Under Federal Rule of Evidence 901(a), “The requirement of authentication … is satisfied by evidence sufficient to support a finding that the matter in question is what its proponent claims.” United States v. Simpson, 152 F.3d 1241, 1249 (10th Cir. 1998).

Ideally, a proponent of the evidence can rely on uncontroverted direct testimony from the creator of the web page in question. In many cases, however, that option is not available. In such situations, the testimony of the viewer/collector of the Internet evidence “in combination with circumstantial indicia of authenticity (such as the dates and web addresses), would support a finding” that the website documents are what the proponent asserts. Perfect 10, Inc. v. Cybernet Ventures, Inc. (C.D.Cal.2002) 213 F.Supp.2d 1146, 1154. (emphasis added) (See also, Lorraine v. Markel American Insurance Company, 241 F.R.D. 534, 546 (D.Md. May 4, 2007) (citing Perfect 10, and referencing MD5 hash values as an additional element of potential “circumstantial indicia” for authentication of electronic evidence).

One of the many benefits of X1 Social Discovery is its ability to preserve and display all the available “circumstantial indicia” – to borrow the Perfect 10 court’s term — to the user in order to present the best case possible for the authenticity of Internet-based evidence collected with the software. This includes collecting all available metadata and generating a MD5 checksum or “hash value” of the preserved data.

But html web pages pose unique authentication challenges and merely generating an MD5 checksum of the entire web page, or just the web page source file, provides limited value because web pages are constantly changing due to their very fluid and dynamic nature. In fact, a web page collected from the Internet in immediate succession would very likely calculate two different MD5 checksums. This is because web pages typically feature links to many external items that are dynamically loaded upon each page view. These external links take the form of cascading style sheets (CSS), graphical images, JavaScripts and other supporting files. This linked content can be stored on another server in the same domain, but is often located somewhere else on the Internet.

When the Web browser loads a web page, it consolidates all these items into one viewable page for the user. Since the Web page source file contains only the links to the files to be loaded, the MD5 checksum of the source file can remain unchanged even if the content of the linked files become completely different.  Therefore, the content of the linked items must be considered in the authenticity of the Web page. X1 Social Discovery addresses these challenges by first generating an MD5 checksum log representing each item that constitutes the Web page, including the main Web page’s source. Then an MD5 representing the content of all the items contained within the web page is generated and preserved.

To further complicate Web collections, entire sections of a Web page are often not visible to the viewer. These hidden areas serve various purposes, including metatagging for Internet search engine optimization. The servers that host Websites can either store static Web pages or dynamically created pages that usually change each time a user visits the Website, even though the actual content may appear unchanged.

In order to address this additional challenge, X1 Social Discovery utilizes two different MD5 fields for each item that makes a Web page.  The first is the acquisition hash that is from the actual collected information.  The second is the content hash.  The content hash is based on the actual “BODY” of a Web page and ignores the hidden metadata.  By taking this approach, the content hash will show if the user viewable content has actually changed, not just a hidden metadata tag provided by the server. To illustrate, below is a screenshot from the metadata view of X1 Social Discovery for website capture evidence, reflecting the generation of MD5 checksums for individual objects on a single webpage:

The time stamp of the capture and url of the web page is also documented in the case. By generating hash values of all individual objects within the web page, the examiner is better able to pinpoint any changes that may have occurred in subsequent captures. Additionally, if there is specific item appearing on the web page, such as an incriminating image, then is it is important to have an individual MD5 checksum of that key piece of evidence. Finally, any document file found on a captured web page, such as a pdf, Powerpoint, or Word document, will also be individually collected by X1 Social Discovery with corresponding acquisition and content hash values generated.

We believe this approach to authentication of website evidence is unique in its detail and presents a new standard. This authentication process supports the equally innovative automated and integrated web collection capabilities of X1 Social Discovery, which is the only solution of its kind to collect website evidence both through a one-off capture or full crawling, including on a scheduled basis, and have that information instantly reviewable in native file format through a federated search that includes multiple pieces of social media and website evidence in a single case. In all, X1 Social Discovery is a powerful solution to effectively collect from social media and general websites across the web for both relevant content and all available “circumstantial indicia.”

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Filed under Authentication, Best Practices, Preservation & Collection