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Polish
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fgrieu
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The OTP is not quite a cipher per the modern definition of that, which requires ability to encryptsencrypt several messages with the same key.

Also, Work Factor is defined only for feasible tasks.

Thus there's no tension between the true facts stated in the question, and nothing to further reconcile.


Note: when the work factor to break a cipher is (proportional to) the key length $k$, the algorithm is extremely poor. Good encryption algorithms have work factor to break them with ordinary computers roughly proportional to $\mathcal O(2^k)$$2^k$, where $k$ is expressed in bitbits.

The OTP is not quite a cipher per the modern definition of that, which requires ability to encrypts several messages with the same key.

Also, Work Factor is defined only for feasible tasks.

Thus there's no tension between the true facts stated in the question, and nothing to further reconcile.


Note: when the work factor to break a cipher is (proportional to) the key length $k$, the algorithm is extremely poor. Good algorithms have work factor $\mathcal O(2^k)$, where $k$ is in bit.

The OTP is not quite a cipher per the modern definition of that, which requires ability to encrypt several messages with the same key.

Also, Work Factor is defined only for feasible tasks.

Thus there's no tension between the true facts stated in the question.


Note: when the work factor to break a cipher is (proportional to) the key length $k$, the algorithm is extremely poor. Good encryption algorithms have work factor to break them with ordinary computers roughly proportional to $2^k$, where $k$ is expressed in bits.

Polish
Source Link
fgrieu
  • 145.5k
  • 12
  • 319
  • 611

The OTP is not quite a cipher per the modern definition of that, which requires ability to encrypts several messages with the same key.

Also, Work Factor is defined only for feasible tasks.

Thus there's no tension between the other true facts stated in the question, and nothing to further reconcile.


Note: when the work factor to break a cipher is (proportional to) the key length $k$, the algorithm is extremely poor. Good algorithms have work factor $\mathcal O(2^k)$, where $k$ is the key length in bit.

The OTP is not quite a cipher per the modern definition of that, which requires ability to encrypts several messages with the same key.

Also, Work Factor is defined only for feasible tasks.

Thus there's no tension between the other true facts stated in the question, and nothing to further reconcile.


Note: when the work factor to break a cipher is (proportional to) the key length $k$, the algorithm is extremely poor. Good algorithms have work factor $\mathcal O(2^k)$, where $k$ is the key length in bit.

The OTP is not quite a cipher per the modern definition of that, which requires ability to encrypts several messages with the same key.

Also, Work Factor is defined only for feasible tasks.

Thus there's no tension between the true facts stated in the question, and nothing to further reconcile.


Note: when the work factor to break a cipher is (proportional to) the key length $k$, the algorithm is extremely poor. Good algorithms have work factor $\mathcal O(2^k)$, where $k$ is in bit.

Source Link
fgrieu
  • 145.5k
  • 12
  • 319
  • 611

The OTP is not quite a cipher per the modern definition of that, which requires ability to encrypts several messages with the same key.

Also, Work Factor is defined only for feasible tasks.

Thus there's no tension between the other true facts stated in the question, and nothing to further reconcile.


Note: when the work factor to break a cipher is (proportional to) the key length $k$, the algorithm is extremely poor. Good algorithms have work factor $\mathcal O(2^k)$, where $k$ is the key length in bit.