DC: Filelock Homes, the digital detective

The digital decoding process

In the second task of today’s Digital Curation lab session, Amy, Taylor, Colm and I decoded three questions, which have been encoded in different common digital formats.  Principally, the task made us aware of three widely used encoding systems: binary, hexademical and Base 64. With the help of two straightforward online decoders we were able to decode the three formats without any difficulties. We simply had to insert the encoded data in the corresponding box and let the website work for us. Google search queries then led us to the answers of the revealed questions.

 

The encoded questions and their answers

Question 1: Binary encoding

On March 11, 1968, President Lyndon B. Johnson mandated that all computers purchased by the United States federal government do something.  What was it?

President Johnson mandated that all these computers support the ASCII (American Standard Code for Information Exchange) character encoding standard.

Sources:

linking to: Lyndon B. Johnson (March 11, 1968). Memorandum Approving the Adoption by the Federal Government of a Standard Code for Information Interchange. The American Presidency Project. Accessed 2008-04-14

 

Question 2: Hexademical encoding

The vigesimal system was memorably employed by a U.S. president when dedicating a cemetery.  Which president, and what decimal value did he express in vigesimal notation?  Hint: in Old Norse, a notch on a stick used to tally values in vigesimal notation was called a “skor.”

It was President Abraham Lincoln who referred to the vigesimal system. He used the decimal value of 20, on which this numeral system is based (Latin vicesimus means ‘twentieth’).

Source:

 

Question 3: Base 64 encoding

The decoding of the third question resulted in an image, which we downloaded from the decoding website:

download

The sixty-four characters of Base 64 encoding are comprised of  the capital letters A-Z, lower case letters a-z, numbers 0-9 and the two special characters + and /.

According to the source, “Base64 represents binary data in an ASCII string format by translating it into a radix-64 representation.”

The characters are listed in the Base 64 index table:

Value Char Value Char Value Char Value Char
0 A 16 Q 32 g 48 w
1 B 17 R 33 h 49 x
2 C 18 S 34 i 50 y
3 D 19 T 35 j 51 z
4 E 20 U 36 k 52 0
5 F 21 V 37 l 53 1
6 G 22 W 38 m 54 2
7 H 23 X 39 n 55 3
8 I 24 Y 40 o 56 4
9 J 25 Z 41 p 57 5
10 K 26 a 42 q 58 6
11 L 27 b 43 r 59 7
12 M 28 c 44 s 60 8
13 N 29 d 45 t 61 9
14 O 30 e 46 u 62 +
15 P 31 f 47 v 63 /

 

Source:

 

Applied Decoding Tools

  • UTF8 to Binary, Hexademical and Base 64 Converter:

https://sites.google.com/site/nathanlexwww/tools/utf8-convert

  • Base 64 Encoder /Decoder:

http://www.freeformatter.com/base64-encoder.html

 

All sources accessed on 11 January 2017.

 

 

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s