Statistics

This page briefly outlines the cost of building a cheap beowulf-like cluster to use dkbf to crack NT passwords. The numbers used are general and for proof-of-concept only. Your mileage WILL vary. The numbers here are out-of-date, which is good for you - bad for sys admins.

1.
A-Z consists of 26 characters. NT Lanman passwords only have 7 characters in them (see www.L0pht.com). This yields 8,353,082,582 possible "keys". At a (very approximate) rate of 446 k/s/Mhz on a Pentium Pro 200, the L0phtCrack requires 26 hours to brute-force the A-Z keyspace.

2.
As of Dec 2000, the following items were priced using Pricewatch

    Price   Part                                Quantity     Cost
    $179    800 Mhz Pentium PIII                x8           1432
    $2      CPU Fans                            x8             16
    $125    Tyan Tiger 133 Dual CPU M/B         x4            500
    $42     128 MB PC-100 RAM                   x4            168  
    $45     3.2 GB EIDE HD                      x4            180  
    $10     10/100 Mb/s Ethernet NIC            x4             40 
    $5      Floppy Drive                        x4             20
    $10     PCI Video Card                      x4             40 
    $20     ATX Case w/ 230 Watt PSU            x4             80
    $4      Case Fan                            x4             16
    $20     4 port 10 Mb/s Ethernet Hub         x1             20
    $2      CAT 5 Ethernet Cables               x4              8
    $5      PS/2 Keyboard                       x1              5
    $5      Mouse                               x1              5
    $103    14 in. Monitor                      x1            103
    $30     Manual KVM Switch + cables          x1             30
    $24     x40 CD-ROM                          x1             24  
    $2      Scyld Beowulf CD                    x1              2 
    $30     Red Hat 7.0 Distribution            x1             30
______________________________________________________________________
                                                            $ 2719   

Of course, these numbers are rough. No shipping and handling is included which is a significant cost factor. You'll probably have some of these parts already. Estimate does not include replacement parts, warranties, or electricity costs. In other words, this is a rough estimate of cheap parts and keyrates.

3.
Given a small cluster like the one above, which would have combined a 5600 Mhz (less one processor to handle the master process), and given a keyrate of 446 k/s/Mhz (incorrectly assuming perfect linear scaling), a total keyrate of 2,497,600 k/s could be achieved. The following Lanman hash attacks would take:

    Character Set       Keys                        Time 
    A-Z                 8,353,082,582 keys          1 hour
    A-Z,0-9             80,603,140,212 keys         9 hours
    A-Z,0-9,33 symbols  7,555,858,447,479 keys      35 days

Try it out for yourself with the Price:Performance Worksheet