Notes

A strongly encrypted, authentic, and digitally signed information can be difficult to access even for a legitimate user at a crucial time of decision-making. The network or the computer system can be attacked and rendered non-functional by an intruder.

High availability, one of the fundamental aspects of information security, cannot be ensured through the use of cryptography. Other methods are needed to guard against the threats such as denial of service or complete breakdown of information system.

Another fundamental need of information security of selective access control also cannot be realized through the use of cryptography. Administrative controls and procedures are required to be exercised for the same.

Cryptography does not guard against the vulnerabilities and threats that emerge from the poor design of systems, protocols, and procedures. These need to be fixed through proper design and setting up of a defensive infrastructure.

Cryptography comes at cost. The cost is in terms of time and money −

Addition of cryptographic techniques in the information processing leads to delay.

The use of public key cryptography requires setting up and maintenance of public key infrastructure requiring the handsome financial budget.

The security of cryptographic technique is based on the computational difficulty of mathematical problems. Any breakthrough in solving such mathematical problems or increasing the computing power can render a cryptographic technique vulnerable.