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Why does AES has exactly 10 rounds for 128 bit key, 12 for 192 and 14 for 256 bit key size
Is AES-256 weaker than 192 and 128 bit versions?Difference between Rijndael 128 / 256 blocksize implementations? (and impact of block size in general)Does AES-128 have the same strength as AES-256 with a padded key?Is double encryption using AES using different key lengths (128 bit and then 256 bit) vulnerable?AES - What is the advantage of a 256-bit key with a 128-bit block cipher?AES key and block sizeWhat are pros and cons of AES/CBC/PKCS5Padding vs AES/GCM/NoPadding for key wrapping?Is there any compelling or logical reason to use AES-192 over AES-128 but not use AES-256?Are tags longer than 128 bit possible for AES-256-CCM and AES-256-GCM?AES key expansion for 192-bit
$begingroup$
I was reading AES algorithm to be used in one of our projects and found that there are exact number of rounds fixed in AES for specific key sizes.
128 bit key size -> 10 rounds
192 bit key size -> 12 rounds
256 bit key size -> 14 rounds
Why these specific number of rounds only ?
aes
asked 2 hours ago
kapilkapil
232
New contributor
kapil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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add a comment |
$begingroup$
I was reading AES algorithm to be used in one of our projects and found that there are exact number of rounds fixed in AES for specific key sizes.
128 bit key size -> 10 rounds
192 bit key size -> 12 rounds
256 bit key size -> 14 rounds
Why these specific number of rounds only ?
aes
asked 2 hours ago
kapilkapil
232
New contributor
kapil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
I was reading AES algorithm to be used in one of our projects and found that there are exact number of rounds fixed in AES for specific key sizes.
128 bit key size -> 10 rounds
192 bit key size -> 12 rounds
256 bit key size -> 14 rounds
Why these specific number of rounds only ?
aes
asked 2 hours ago
kapilkapil
232
New contributor
kapil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
I was reading AES algorithm to be used in one of our projects and found that there are exact number of rounds fixed in AES for specific key sizes.
128 bit key size -> 10 rounds
192 bit key size -> 12 rounds
256 bit key size -> 14 rounds
Why these specific number of rounds only ?
aes
aes
asked 2 hours ago
kapilkapil
232
New contributor
kapil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
kapilkapil
232
New contributor
kapil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
kapilkapil
232
New contributor
kapil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 hours ago
kapilkapil
232
asked 2 hours ago
kapilkapil
232
232
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kapil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
kapil is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
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1 Answer
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$begingroup$
Why these specific number of rounds only?
Because AES is a standard; AES is an acronym for "Advanced Encryption Standard".
The standard specifies these specific number of rounds to ensure that different implementations are interoperable.
Why not more or less?
The reason these specific numbers of rounds were chosen was a choice of the designers. They did a lot of math to determine that these were the sweet spot between sufficient security and optimal performance.
Less might be insecure, and more might be slower with no benefit.
To quote the above book (from Section 3.5 The Number of Rounds):
For Rijndael versions with a longer key, the number of rounds was raised by one for every additional 32 bits in the cipher key. This was done for the following reasons:
One of the main objectives is the absence of shortcut attacks, i.e. attacks that are more efficient than an exhaustive key search. Since the workload of an exhaustive key search grows with the key length, shortcut attacks can afford to be less efficient for longer keys.
(Partially) known-key and related-key attacks exploit the knowledge of cipher key bits or the ability to apply different cipher keys. If the cipher key grows, the range of possibilities available to the cryptanalyst increases.
edited 23 mins ago
puzzlepalace
2,8701133
answered 1 hour ago
Ella Rose♦Ella Rose
16.4k44281
$endgroup$
add a comment |
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1 Answer
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1 Answer
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$begingroup$
Why these specific number of rounds only?
Because AES is a standard; AES is an acronym for "Advanced Encryption Standard".
The standard specifies these specific number of rounds to ensure that different implementations are interoperable.
Why not more or less?
The reason these specific numbers of rounds were chosen was a choice of the designers. They did a lot of math to determine that these were the sweet spot between sufficient security and optimal performance.
Less might be insecure, and more might be slower with no benefit.
To quote the above book (from Section 3.5 The Number of Rounds):
For Rijndael versions with a longer key, the number of rounds was raised by one for every additional 32 bits in the cipher key. This was done for the following reasons:
One of the main objectives is the absence of shortcut attacks, i.e. attacks that are more efficient than an exhaustive key search. Since the workload of an exhaustive key search grows with the key length, shortcut attacks can afford to be less efficient for longer keys.
(Partially) known-key and related-key attacks exploit the knowledge of cipher key bits or the ability to apply different cipher keys. If the cipher key grows, the range of possibilities available to the cryptanalyst increases.
edited 23 mins ago
puzzlepalace
2,8701133
answered 1 hour ago
Ella Rose♦Ella Rose
16.4k44281
$endgroup$
add a comment |
$begingroup$
Why these specific number of rounds only?
Because AES is a standard; AES is an acronym for "Advanced Encryption Standard".
The standard specifies these specific number of rounds to ensure that different implementations are interoperable.
Why not more or less?
The reason these specific numbers of rounds were chosen was a choice of the designers. They did a lot of math to determine that these were the sweet spot between sufficient security and optimal performance.
Less might be insecure, and more might be slower with no benefit.
To quote the above book (from Section 3.5 The Number of Rounds):
For Rijndael versions with a longer key, the number of rounds was raised by one for every additional 32 bits in the cipher key. This was done for the following reasons:
One of the main objectives is the absence of shortcut attacks, i.e. attacks that are more efficient than an exhaustive key search. Since the workload of an exhaustive key search grows with the key length, shortcut attacks can afford to be less efficient for longer keys.
(Partially) known-key and related-key attacks exploit the knowledge of cipher key bits or the ability to apply different cipher keys. If the cipher key grows, the range of possibilities available to the cryptanalyst increases.
edited 23 mins ago
puzzlepalace
2,8701133
answered 1 hour ago
Ella Rose♦Ella Rose
16.4k44281
$endgroup$
add a comment |
$begingroup$
Why these specific number of rounds only?
Because AES is a standard; AES is an acronym for "Advanced Encryption Standard".
The standard specifies these specific number of rounds to ensure that different implementations are interoperable.
Why not more or less?
The reason these specific numbers of rounds were chosen was a choice of the designers. They did a lot of math to determine that these were the sweet spot between sufficient security and optimal performance.
Less might be insecure, and more might be slower with no benefit.
To quote the above book (from Section 3.5 The Number of Rounds):
For Rijndael versions with a longer key, the number of rounds was raised by one for every additional 32 bits in the cipher key. This was done for the following reasons:
One of the main objectives is the absence of shortcut attacks, i.e. attacks that are more efficient than an exhaustive key search. Since the workload of an exhaustive key search grows with the key length, shortcut attacks can afford to be less efficient for longer keys.
(Partially) known-key and related-key attacks exploit the knowledge of cipher key bits or the ability to apply different cipher keys. If the cipher key grows, the range of possibilities available to the cryptanalyst increases.
edited 23 mins ago
puzzlepalace
2,8701133
answered 1 hour ago
Ella Rose♦Ella Rose
16.4k44281
$endgroup$
Why these specific number of rounds only?
Because AES is a standard; AES is an acronym for "Advanced Encryption Standard".
The standard specifies these specific number of rounds to ensure that different implementations are interoperable.
Why not more or less?
The reason these specific numbers of rounds were chosen was a choice of the designers. They did a lot of math to determine that these were the sweet spot between sufficient security and optimal performance.
Less might be insecure, and more might be slower with no benefit.
To quote the above book (from Section 3.5 The Number of Rounds):
For Rijndael versions with a longer key, the number of rounds was raised by one for every additional 32 bits in the cipher key. This was done for the following reasons:
One of the main objectives is the absence of shortcut attacks, i.e. attacks that are more efficient than an exhaustive key search. Since the workload of an exhaustive key search grows with the key length, shortcut attacks can afford to be less efficient for longer keys.
(Partially) known-key and related-key attacks exploit the knowledge of cipher key bits or the ability to apply different cipher keys. If the cipher key grows, the range of possibilities available to the cryptanalyst increases.
edited 23 mins ago
puzzlepalace
2,8701133
answered 1 hour ago
Ella Rose♦Ella Rose
16.4k44281
edited 23 mins ago
puzzlepalace
2,8701133
edited 23 mins ago
puzzlepalace
2,8701133
edited 23 mins ago
puzzlepalace
2,8701133
2,8701133
answered 1 hour ago
Ella Rose♦Ella Rose
16.4k44281
answered 1 hour ago
Ella Rose♦Ella Rose
16.4k44281
answered 1 hour ago
Ella Rose♦Ella Rose
16.4k44281
16.4k44281
add a comment |
add a comment |
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