Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your International Data Encryption Algorithm shopping experience:
1. Compare - without doubt the biggest advantage that the International Data Encryption Algorithm offers shoppers today is the ability to compare thousands of International Data Encryption Algorithm at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a International Data Encryption Algorithm? Wrong! If the International Data Encryption Algorithm is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about International Data Encryption Algorithm then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling International Data Encryption Algorithm? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about International Data Encryption Algorithm and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your International Data Encryption Algorithm wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your International Data Encryption Algorithm then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the International Data Encryption Algorithm site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about International Data Encryption Algorithm, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your International Data Encryption Algorithm, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
{{Infobox block cipher| name = IDEA| image = | caption = An encryption round of IDEA| designers = James Massey, Xuejia Lai, [MESH (cipher), Akelarre (cipher), IDEA NXT (FOX)]| rounds = 8.5| cryptanalysis = A collision attack requiring 224 chosen plaintexts breaks 5 rounds with a complexity of 2126 (Demirci et al, 2003).-->
In cryptography, the
International Data Encryption Algorithm (
IDEA) is a
block cipher designed by
Xuejia Lai and James Massey of
ETH Zurich and was first described in 1991. The algorithm was intended as a replacement for the
Data Encryption Standard. IDEA is a minor revision of an earlier cipher,
PES (Proposed Encryption Standard); IDEA was originally called
IPES (
Improved PES).
The cipher was designed under a research contract with the Hasler Foundation, which became part of Ascom-Tech AG. The cipher is patented in a number of countries but is freely available for non-commercial use. The name "IDEA" is also a trademark. The
patents will expire in 2010–2011. Today, IDEA is licensed worldwide by MediaCrypt.
IDEA was used in Pretty Good Privacy (PGP) v2.0, and was incorporated after the original cipher used in v1.0, BassOmatic, was found to be insecure. IDEA is an optional algorithm in the
OpenPGP standard.
Operation
IDEA operates on 64-bit
block size (cryptography) using a 128-bit key (cryptography), and consists of a series of eight identical transformations (a
round, see the illustration) and an output transformation (the
half-round). The processes for encryption and decryption are similar. IDEA derives much of its security by interleaving operations from different
group (mathematics) — modular arithmetic addition and multiplication, and bitwise XOR — which are algebraically "incompatible" in some sense. In more detail, these operators, which all deal with 16-bit quantities, are:
- Bitwise XOR (denoted with a blue ⊕).
- Addition modulo 216 (denoted with a green ).
- Multiplication modulo 216+1, where the all-zero word (0x0000) is interpreted as 216 (denoted by a red ).
After the eight rounds comes a final "half round", the output transformation illustrated below:
Security
The designers analysed IDEA to measure its strength against
differential cryptanalysis and concluded that it is immune under certain assumptions. No successful
linear cryptanalysis or algebraic weaknesses have been reported. Some classes of
weak keys have been found — E.g. (Daemen et al, 1994) — but these are of little concern in practice, being so rare as to be unnecessary to avoid explicitly.
As of 2004, the best attack which applies to all keys can break IDEA reduced to 5 rounds (the full IDEA cipher uses 8.5 rounds) (Demirci et al, 2003).
Bruce Schneier thought highly of IDEA in 1996, writing, "In my opinion, it is the best and most secure block algorithm available to the public at this time." (
Applied Cryptography, 2nd ed.) However, by 1999 he was no longer recommending IDEA due to the availability of faster algorithms, some progress in its cryptanalysis, and the issue of patents .
IDEA is patented in Austria, France, Germany,
Italy, Netherlands,
Spain,
Sweden,
Switzerland,
United Kingdom, (European patent EP-B-0482154), the United States ( US patent #5,214,703, issued May 25, 1993) and Japan (JP 3225440).
MediaCrypt is now also offering a successor to IDEA and focuses on its new cipher (official release on May 2005) IDEA NXT, which was previously called FOX.
References
- Joan Daemen, R. Govaerts, and Joos Vandewalle, Weak keys for IDEA, CRYPTO '93. pp224–231.
- Hüseyin Demirci, Erkan Türe, Ali Aydin Selçuk, A New Meet in the Middle Attack on The IDEA Block Cipher, 10th Annual Workshop on Selected Areas in Cryptography, 2003.
- Xuejia Lai and James L. Massey, A Proposal for a New Block Encryption Standard, EUROCRYPT 1990, pp389–404
- Xuejia Lai and James L. Massey and S. Murphy, Markov ciphers and differential cryptanalysis, Advances in Cryptology — Eurocrypt '91, Springer-Verlag (1992), pp17–38.
External links
- RSA FAQ on Block Ciphers
- Mediacrypt homepage — IDEA licensor
- SCAN entry for IDEA
- Helger Lipmaa's links for IDEA
- IDEA in 448 bytes of 80x86
{{Infobox block cipher| name = IDEA| image = | caption = An encryption round of IDEA| designers = James Massey, Xuejia Lai, [MESH (cipher),
Akelarre (cipher),
IDEA NXT (FOX)]| rounds = 8.5| cryptanalysis = A collision attack requiring 224 chosen plaintexts breaks 5 rounds with a complexity of 2126 (Demirci et al, 2003).-->
In cryptography, the
International Data Encryption Algorithm (
IDEA) is a
block cipher designed by
Xuejia Lai and James Massey of ETH Zurich and was first described in 1991. The algorithm was intended as a replacement for the
Data Encryption Standard. IDEA is a minor revision of an earlier
cipher,
PES (Proposed Encryption Standard); IDEA was originally called
IPES (
Improved PES).
The cipher was designed under a research contract with the Hasler Foundation, which became part of Ascom-Tech AG. The cipher is patented in a number of countries but is freely available for non-commercial use. The name "IDEA" is also a trademark. The
patents will expire in 2010–2011. Today, IDEA is licensed worldwide by MediaCrypt.
IDEA was used in
Pretty Good Privacy (PGP) v2.0, and was incorporated after the original cipher used in v1.0,
BassOmatic, was found to be insecure. IDEA is an optional algorithm in the OpenPGP standard.
Operation
IDEA operates on 64-bit block size (cryptography) using a 128-bit key (cryptography), and consists of a series of eight identical transformations (a
round, see the illustration) and an output transformation (the
half-round). The processes for encryption and decryption are similar. IDEA derives much of its security by interleaving operations from different group (mathematics) —
modular arithmetic addition and multiplication, and bitwise
XOR — which are algebraically "incompatible" in some sense. In more detail, these operators, which all deal with 16-bit quantities, are:
- Bitwise XOR (denoted with a blue ⊕).
- Addition modulo 216 (denoted with a green ).
- Multiplication modulo 216+1, where the all-zero word (0x0000) is interpreted as 216 (denoted by a red ).
After the eight rounds comes a final "half round", the output transformation illustrated below:
Security
The designers analysed IDEA to measure its strength against
differential cryptanalysis and concluded that it is immune under certain assumptions. No successful linear cryptanalysis or algebraic weaknesses have been reported. Some classes of
weak keys have been found — E.g. (Daemen et al, 1994) — but these are of little concern in practice, being so rare as to be unnecessary to avoid explicitly.
As of 2004, the best attack which applies to all keys can break IDEA reduced to 5 rounds (the full IDEA cipher uses 8.5 rounds) (Demirci et al, 2003).
Bruce Schneier thought highly of IDEA in 1996, writing, "In my opinion, it is the best and most secure block algorithm available to the public at this time." (
Applied Cryptography, 2nd ed.) However, by 1999 he was no longer recommending IDEA due to the availability of faster algorithms, some progress in its cryptanalysis, and the issue of patents .
IDEA is patented in
Austria, France, Germany, Italy,
Netherlands, Spain,
Sweden,
Switzerland, United Kingdom, (European patent EP-B-0482154), the
United States ( US patent #5,214,703, issued May 25, 1993) and
Japan (JP 3225440).
MediaCrypt is now also offering a successor to IDEA and focuses on its new cipher (official release on May 2005)
IDEA NXT, which was previously called FOX.
References
- Joan Daemen, R. Govaerts, and Joos Vandewalle, Weak keys for IDEA, CRYPTO '93. pp224–231.
- Hüseyin Demirci, Erkan Türe, Ali Aydin Selçuk, A New Meet in the Middle Attack on The IDEA Block Cipher, 10th Annual Workshop on Selected Areas in Cryptography, 2003.
- Xuejia Lai and James L. Massey, A Proposal for a New Block Encryption Standard, EUROCRYPT 1990, pp389–404
- Xuejia Lai and James L. Massey and S. Murphy, Markov ciphers and differential cryptanalysis, Advances in Cryptology — Eurocrypt '91, Springer-Verlag (1992), pp17–38.
External links
- RSA FAQ on Block Ciphers
- Mediacrypt homepage — IDEA licensor
- SCAN entry for IDEA
- Helger Lipmaa's links for IDEA
- IDEA in 448 bytes of 80x86
International Data Encryption Algorithm from FOLDOC
International Data Encryption Algorithm < algorithm, cryptography > (IDEA) A conventional encryption algorithm, written by Xuejia Lai and James Massey, in 1992.
International Data Encryption Algorithm - Wikipedia, the free ...
In cryptography, the International Data Encryption Algorithm (IDEA) is a block cipher designed by Xuejia Lai and James Massey of ETH Zurich and was first described in 1991.
International Data Encryption Algorithm
The Free Online Dictionary of Computing (http://foldoc.doc.ic.ac.uk/) is edited by Denis Howe < dbh@doc.ic.ac.uk >. Previous: International Core War Society Next: International ...
International Data Encryption Algorithm - Definition at Your ...
Developed by Xuejia Lai and James Massey in 1992. A block cipher, IDEA operates on 64-bit blocks with a 128-bit key and is considered to be very secure.
International Data Encryption Algorithm definition of International ...
algorithm, cryptography) International Data Encryption Algorithm - (IDEA) A conventional encryption algorithm, written by Xuejia Lai and James Massey, in 1992.
International Function Point Users Group from FOLDOC
International Function Point Users Group < body, programming > (IFPUG) A ... Nearby terms: International Data Encryption Algorithm « International Electrotechnical Commission « ...
IDEA - International Data Encryption Algorithm
IDEA - International Data Encryption Algorithm Acronyms: IDEA. See also: Block encryption; Secret key cryptography. International Data Encryption Algorithm (IDEA)
What is International Data Encryption Algorithm? - a definition from ...
IDEA (International Data Encryption Algorithm) is an encryption algorithm developed at ETH in Zurich, Switzerland. It uses a block cipher with a 128-bit key, and is generally ...
Google Dictionary:international data encryption algorithm in English
Google's free online dictionary service. ... No dictionary translations were found for: international data encryption algorithm in Spanish
International Data Encryption Algorithm definition |Dictionary.com ...
Sponsored Links Data Encryption Algorithm Safeguard Your Data & Protect Your Reputation with McAfee. Learn More! www.McAfee.com
