In this lab, you will explore the best and worst use of a popular message digest algorithm. For this one, we shall focus on MD5, but all of this can be applied to the other ones, such as SHA-1.

In the best use portion, you will discover and outline a specific implementation of the MD5 algorithm, where it provides high value and a very low security risk.

In contrast, in the worst use portion, you will attempt to crack an MD5 hash (this is ethical hacking) and suggest a scenario where the worst use practice may actually be implemented.

The reason for this lab is to give you an understanding of how cryptography can be properly and improperly used and how changes in technology may serve to weaken trusted cryptographic applications.

Document Authoring Guidelines

Each section will vary in size based on the requirements. Drive yourself to create a useful document for the setting you have selected.

Lab Document Framework

Best Use of MD5 or SHA-1: Outline a scenario where the MD5 or SHA-1 algorithms are put to good and proper use. Start by stating what the algorithm does and give a use case where either MD5 or SHA-1 has a best fit condition. It is generally about 5–10 sentences.

Ethical Hacking of MD5: Copy the following text into your lab document and fill in the blanks.

MD5 Hash 1: 4eefef62c45d66f55d89c515d8352c5c Input was: _____

MD5 Hash 2: 5f4dcc3b5aa765d61d8327deb882cf99 Input was: _____

MD5 Hash 3: d6a6bc0db10694a2d90e3a69648f3a03 Input was: _____

Worst Use of MD5 or SHA-1: Outline a scenario where the MD5 or SHA-1 algorithms are put to poor or improper use. Start by stating what improper assumptions were made and how it did (or could) lead to a security compromise. It is generally about 5–10 sentences.

Citations and Resources Used in This Report: Tell us where you received external guidance and ideas. If you have presented original ideas, then give yourself credit, and tell us why you believe it is correct.

Delivering Your Lab Document

Organize your materials into a single comprehensive document. Name your document(s) such that the course ID, your full name, and this lab’s name are referenced. For example, include SEC572_FirstName_LastName_Lab3 in the file’s name. Your document must be readable with Microsoft Word 2007 (or prior) or a standard PDF file viewer.

Submit your assignment to the Week 3 Dropbox, located at the top of this page. (See the Syllabus section “Due Dates for Assignments & Exams” for due date information.)

Use the Dropbox comment area to give your instructor an introduction, or state any special information.

Step 1: Best Use

Outline a scenario where the MD5 or SHA-1 algorithms are put to good and proper use.

Step 2: Ethical Hacking of MD5

Crack the following three MD5 hash values and publish the plaintext in your lab document. See ethical hacking help at the bottom of this lab page for some hints.

MD5 hash 1: 4eefef62c45d66f55d89c515d8352c5c  

MD5 hash 2: 5f4dcc3b5aa765d61d8327deb882cf99  

MD5 hash 3: d6a6bc0db10694a2d90e3a69648f3a03 

Step 3: Worst Use

Outline a scenario where the MD5 or SHA-1 algorithms could be (or have been) put to poor and improper use.

Suggested Resources: