The concept is introduced here of extending Triple-DES to five keys, rather than three keys, named Quintuple-DES.
Algorithm
Quintuple-DES uses a "key bundle" which comprises five DES keys, K<sub>1</sub>, K<sub>2</sub>, K<sub>3</sub>, K<sub>4</sub> and K<sub>5</sub>, each of 56 bits (excluding parity bits). The encryption algorithm is:
:ciphertext = E<sub>K5</sub>(D<sub>K4</sub>(E<sub>K3</sub>(D<sub>K2</sub>(E<sub>K1</sub>(plaintext)))))
I.e., DES encrypt with K<sub>1</sub>, DES decrypt with K<sub>2</sub>, DES encrypt with K<sub>3</sub>, DES decrypt with K<sub>4</sub>, then DES encrypt with K<sub>5</sub>.
Decryption is the reverse:
:plaintext = D<sub>K1</sub>(E<sub>K2</sub>(D<sub>K3</sub>(E<sub>K4</sub>(D<sub>K5</sub>(ciphertext)))))
I.e., decrypt with K<sub>5</sub>, encrypt with K<sub>4</sub>, decrypt with K<sub>3</sub>, encrypt with K<sub>2</sub>, then decrypt with K<sub>1</sub>.
Each quintuple encryption encrypts one block of 64 bits of data.
In each case the second and fourth operations are the reverse of the first, third, and last. This improves the strength of the algorithm.
Keying options
The standards define three keying options:
*Keying option 1: All five keys are independent.
*Keying option 2: K<sub>1</sub>, K<sub>2</sub>, and K<sub>3</sub> are independent, and K<sub>4</sub> K<sub>3</sub>, and K<sub>5</sub> K<sub>3</sub>.
Keying option 1 is the strongest, with 5 × 56 = 280 independent key bits.
Keying option 2 provides less security, with 3 × 56 168 key bits. Keying option 2 is equivalent to Triple-DES, with only 3 × 56 168 key bits. This option provides backward compatibility with Triple-DES, because the last two DES operations cancel out.
Each DES key is nominally stored or transmitted as 8 bytes, each of odd parity. According to ANSI X3.92-1981 (one of the standards that defines the DES algorithm), section 3.5: "One bit in each 8-bit byte of the KEY may be utilized for error detection in key generation, distribution, and storage. Bits 8, 16,..., 64 are for use in ensuring that each byte is of odd parity."
so a key bundle requires 40 or 24 bytes, for keying option 1 or 2 respectively.
Considerations
The Quintuple-DES and Triple-DES algorithms may be considered slow and cumbersome, and there are better alternatives. However, DES and Triple-DES have a long history of analysis and have survived the test-of-time without being cracked. New algorithms carry the risk of being cracked.
Algorithm
Quintuple-DES uses a "key bundle" which comprises five DES keys, K<sub>1</sub>, K<sub>2</sub>, K<sub>3</sub>, K<sub>4</sub> and K<sub>5</sub>, each of 56 bits (excluding parity bits). The encryption algorithm is:
:ciphertext = E<sub>K5</sub>(D<sub>K4</sub>(E<sub>K3</sub>(D<sub>K2</sub>(E<sub>K1</sub>(plaintext)))))
I.e., DES encrypt with K<sub>1</sub>, DES decrypt with K<sub>2</sub>, DES encrypt with K<sub>3</sub>, DES decrypt with K<sub>4</sub>, then DES encrypt with K<sub>5</sub>.
Decryption is the reverse:
:plaintext = D<sub>K1</sub>(E<sub>K2</sub>(D<sub>K3</sub>(E<sub>K4</sub>(D<sub>K5</sub>(ciphertext)))))
I.e., decrypt with K<sub>5</sub>, encrypt with K<sub>4</sub>, decrypt with K<sub>3</sub>, encrypt with K<sub>2</sub>, then decrypt with K<sub>1</sub>.
Each quintuple encryption encrypts one block of 64 bits of data.
In each case the second and fourth operations are the reverse of the first, third, and last. This improves the strength of the algorithm.
Keying options
The standards define three keying options:
*Keying option 1: All five keys are independent.
*Keying option 2: K<sub>1</sub>, K<sub>2</sub>, and K<sub>3</sub> are independent, and K<sub>4</sub> K<sub>3</sub>, and K<sub>5</sub> K<sub>3</sub>.
Keying option 1 is the strongest, with 5 × 56 = 280 independent key bits.
Keying option 2 provides less security, with 3 × 56 168 key bits. Keying option 2 is equivalent to Triple-DES, with only 3 × 56 168 key bits. This option provides backward compatibility with Triple-DES, because the last two DES operations cancel out.
Each DES key is nominally stored or transmitted as 8 bytes, each of odd parity. According to ANSI X3.92-1981 (one of the standards that defines the DES algorithm), section 3.5: "One bit in each 8-bit byte of the KEY may be utilized for error detection in key generation, distribution, and storage. Bits 8, 16,..., 64 are for use in ensuring that each byte is of odd parity."
so a key bundle requires 40 or 24 bytes, for keying option 1 or 2 respectively.
Considerations
The Quintuple-DES and Triple-DES algorithms may be considered slow and cumbersome, and there are better alternatives. However, DES and Triple-DES have a long history of analysis and have survived the test-of-time without being cracked. New algorithms carry the risk of being cracked.
Robert Birdsall (born 28 March 1991) is an Irish footballer who plays as goalkeeper for Cobh Ramblers in the League of Ireland.
Birdsall was born in Keighley, England. He played youth football in County Kerry, Ireland, with Kingdom Boys and Tralee Dynamos. Birdsall signed for Cork City in 2008 at the age of 16 and featured in the youth and reserve set up.
He made his senior team debut in the A championship in 2009 away to . He spent two seasons playing in the League of Ireland A championship. He has since gone on to get a call up to the Republic of Ireland national under-21 football team.
During the 2011/12 season Birdsall had a spell with Bradford City. He lined out a number of times in the reserves, His first game was a 2-1 defeat to Middlesbrough at Valley Parade in which he made a double penalty save.
Birdsall then signed for Blyth Spartans in the Blue Square Conference North in September 2011 and made his debut in a 3-3 draw with Bishop's Stortford F.C. in which he saved a penalty.
In January 2013 Birdsall signed a 2 year endorsement contract to be an ambassador for goalkeeping company 'Westcoast Goalkeeping' in Seattle in the U.S. state of Washington. This contract sees him as an ambassador for the brand until end of year 2014.
In February 2013 Birdsall signed for Cobh Ramblers in the League of Ireland First Division.
Birdsall has also lined out twice for Liverpool as a Trialist in 2011.
He also had spells as a trialist in reserve matches with Leeds United.
Birdsall was born in Keighley, England. He played youth football in County Kerry, Ireland, with Kingdom Boys and Tralee Dynamos. Birdsall signed for Cork City in 2008 at the age of 16 and featured in the youth and reserve set up.
He made his senior team debut in the A championship in 2009 away to . He spent two seasons playing in the League of Ireland A championship. He has since gone on to get a call up to the Republic of Ireland national under-21 football team.
During the 2011/12 season Birdsall had a spell with Bradford City. He lined out a number of times in the reserves, His first game was a 2-1 defeat to Middlesbrough at Valley Parade in which he made a double penalty save.
Birdsall then signed for Blyth Spartans in the Blue Square Conference North in September 2011 and made his debut in a 3-3 draw with Bishop's Stortford F.C. in which he saved a penalty.
In January 2013 Birdsall signed a 2 year endorsement contract to be an ambassador for goalkeeping company 'Westcoast Goalkeeping' in Seattle in the U.S. state of Washington. This contract sees him as an ambassador for the brand until end of year 2014.
In February 2013 Birdsall signed for Cobh Ramblers in the League of Ireland First Division.
Birdsall has also lined out twice for Liverpool as a Trialist in 2011.
He also had spells as a trialist in reserve matches with Leeds United.
Christine Lovatt (born 19 December 1951 as Mary Christine Evans in London, United Kingdom) is an Australian crossword puzzle compiler and co-founder of Lovatts Media Group, an Australian magazine company that publishes crossword and sudoku puzzles.
Early life
She was born and raised in Carshalton, South London to David Evans, a Welsh engineer, and Mary Sullivan, an Irish nurse.
She completed Nurse's training at Guy's Hospital in 1973. In 1974, Christine travelled to Australia for a working holiday, and after several years working as a nurse in Queensland, decided to permanently settle. During this time, she met journalist James Lovatt, and they were married in 1978.
Career
Together with James, she compiled crosswords for several newspapers and magazines, including People. In 1978 they launched their own publishing company.
The first magazine published by Lovatts was Colossus, a collection of Giant crosswords. By 2012, they were publishing 20 titles in Australia and New Zealand, and 4 titles in the United Kingdom. Some of these include BIG, Colossus, Starhunt, Holiday Collection, Mega and Super Sudoku.
Christine Lovatt is best known for her cryptic and giant crosswords. Christine's BIG Crossword has been appearing in for over twenty years and Christine's Cryptic also appears weekly. Her Colossus is a regular feature in the Australian Women's Weekly.
Publicity
Christine has appeared on many Australian TV shows, including A Current Affair, 11am and Simon Townsend's Wonder World and is frequently featured on radio talkshows, including ABC, 2UE, and 4BG (Brisbane).
In March 2009, James and Christine were featured on Conversations with Richard Fidler.
Personal life
Christine has three children in Australia, and splits her time between the NSW Central Coast and Bantry, Ireland.
Early life
She was born and raised in Carshalton, South London to David Evans, a Welsh engineer, and Mary Sullivan, an Irish nurse.
She completed Nurse's training at Guy's Hospital in 1973. In 1974, Christine travelled to Australia for a working holiday, and after several years working as a nurse in Queensland, decided to permanently settle. During this time, she met journalist James Lovatt, and they were married in 1978.
Career
Together with James, she compiled crosswords for several newspapers and magazines, including People. In 1978 they launched their own publishing company.
The first magazine published by Lovatts was Colossus, a collection of Giant crosswords. By 2012, they were publishing 20 titles in Australia and New Zealand, and 4 titles in the United Kingdom. Some of these include BIG, Colossus, Starhunt, Holiday Collection, Mega and Super Sudoku.
Christine Lovatt is best known for her cryptic and giant crosswords. Christine's BIG Crossword has been appearing in for over twenty years and Christine's Cryptic also appears weekly. Her Colossus is a regular feature in the Australian Women's Weekly.
Publicity
Christine has appeared on many Australian TV shows, including A Current Affair, 11am and Simon Townsend's Wonder World and is frequently featured on radio talkshows, including ABC, 2UE, and 4BG (Brisbane).
In March 2009, James and Christine were featured on Conversations with Richard Fidler.
Personal life
Christine has three children in Australia, and splits her time between the NSW Central Coast and Bantry, Ireland.
Candace Duval was the 2012 Democratic nominee in Texas's for the United States House of Representatives. She lost to incumbent Lamar Smith in the general election on November 6, 2012.
Early life and education
Duval was born in Corpus Christi, Texas. She earned an associate degree from Brazosport College in 1991, graduating with honors.
2012 congressional candidacy
Duval filed her statement of candidacy for the 2012 election in Texas's 21st congressional district on January 23, 2012. She faced Daniel Boone in the Democratic primary on May 29, 2012 and won the race with 61.1% of the vote. Duval lost to incumbent Lamar Smith in the general election on November 6, 2012, by a 63% to 33% margin.<ref name="b" />
Early life and education
Duval was born in Corpus Christi, Texas. She earned an associate degree from Brazosport College in 1991, graduating with honors.
2012 congressional candidacy
Duval filed her statement of candidacy for the 2012 election in Texas's 21st congressional district on January 23, 2012. She faced Daniel Boone in the Democratic primary on May 29, 2012 and won the race with 61.1% of the vote. Duval lost to incumbent Lamar Smith in the general election on November 6, 2012, by a 63% to 33% margin.<ref name="b" />