What is the life cycle of a key ?
- 1 Answers
- 3244 Views
- I also Faced
- E-Mail Answers
Answer / ramkumar
Keys have limited lifetimes for a number of reasons. The
most important reason is protection against cryptanalysis.
Each time the key is used, it generates a number of
ciphertexts. Using a key repetitively allows an attacker to
build up a store of ciphertexts (and possibly plaintexts)
which may prove sufficient for a successful cryptanalysis
of the key value. If you suspect that an attacker may have
obtained your key, the your key is considered compromised .
Research in cryptanalysis can lead to possible attacks
against either the key or the algorithm. For example, RSA
key lengths are increased every few years to ensure that
the improved factoring algorithms do not compromise the
security of messages encrypted with RSA.
Another reason for limiting the lifetime of a key is to
minimize the damage from a compromised key. It is unlikely
that a user will discover that his key has been compromised
by an attacker if the attacker remains "passive."
Relatively frequent key changes will limit any potential
damage from compromised keys. Ford [For94] describes the
life cycle of a key as follows:
key generation and possibly registration for a public key
key distribution
key activation/deactivation
key replacement or key update
key revocation
key termination, involving destruction and possibly
archival
| Is This Answer Correct ? | 0 Yes | 0 No |
What are the disadvantages of public-key cryptography compared with secret-key cryptography?
What happens if a private key is compromised ?
What is the elgamal cryptosystem?
Blowfish uses the longest key. Does this mean it is the strongest cipher?
What are "stream" and "block" ciphers?
How is an s-box value of AES can be modified? How is it done?
What are knapsack cryptosystems?
What Is Encryption?
what is pretty good privacy?
What is the rabin signature scheme?
What are the advantages of public-key cryptography compared with secret-key cryptography?
A company wants to transmit data over the telephone, but it is concerned that its phones may be tapped. All of its data is transmitted as four-digit integers. It has asked you to write a program that will encrypt its data so that the data may be transmitted more securely. Your script should read a four digit integer entered by the user in a prompt dialog and encrypt it as follows: Replace each digit by (the sum of that digit plus 7) modulus 10. Then swap the first digit with the third, and swap the second digit with the fourth. Then output XHTML text that displays the encrypted integer.
Cryptography Algorithms 
