Present-day Modern Cryptography Applications
By: Abdul Nasir Muniru
Tags: Cryptography, History Of Technology

Present-day Modern Cryptography Applications

As compared to the modern-day, cryptography before the 2oth century was much focus on linguistic and Lexicographic patterns. However, Modern cryptography combines mathematics, computer science, electrical engineering, communication science, and physics. Also, information theory, computational complexity, statistics, combinatorics, abstract algebra, and number theory as very prominent in modern-day cryptography.

Confidentiality, Data Integrity, Authentication, Authentication, and Non-repudiation are the central theme of modern cryptography.

The invention of rotor motors increases the difficulty of cryptanalyst in decrypting messages. The development of digital electronic computing help in cryptanalysis. It also did not only help in making much more complex ciphers but also made it possible to encrypt any kind of data so long as it can be represented in binary format.

A diagram of the flow of events in Cryptography developments by Abdul Nasir Muniru, XAUT

Unlike the classical ciphers which mechanically manipulated the characters, a good modern cipher turn to be fast, requires few computing resources while breaking it requires a huge magnitude of efforts and larger resources. This makes cryptanalysis inefficient and impractical and close to impossible.

i. Public and Commercial Usage

After the 1970s cryptography usage was now open to the public.

Cryptography could be used commercially but there came a series of controversies as cryptanalyst found faults with the standards.

IBM helped the government to create the first Data Encryption Standard (DES) for the United States Government.

Atala Corporation founded by Mohamed Atalla developed the first Hardware Security Module (HSM) in 1972. It was used to protect offline devices with an unguessable PIN generating key.

ii. Usage of DES and AES

The Data Encryption Standard (DES) and the Advanced Encryption Standard (AES) are block cipher designs that have been designated cryptography standards by the US government (though DES’s designation was finally withdrawn after the AES was adopted) (Esslinger, 2011)

Despite its deprecation as an official standard, DES (especially its still-approved and much more secure triple-DES variant) remains quite popular; it is used across a wide range of applications, from ATM encryption (National Credit Union Administration, 2004) to e-mail privacy (Internet Engineering Task Force, 1998) and secure remote access. (Golen, 2002) Many other block ciphers have been designed and released, with considerable variation in quality. Many, even some designed by capable practitioners, have been thoroughly broken, such as FEAL (Menezes, van Oorschot, & Vanstone, 1997)

iii. RSA

Whitfield Diffie and Martin Hellman novel publication of their key agreement algorithm introduced the world to a new dimension of encryption their RSA was based on mathematical problems that are easy to state but have been found difficult to solve (Diffie & Hellman, November 1976). It promoted the application of cryptography in digital communications, computer networks and security, information exchange, transactions as well as privacy protection.

Aside from the One Time Pad (OTP), RSA is one of the few cryptographic systems that is proven to be secure under certain conditions which is its factoring of extremely large integers.

In public-key cryptosystems, the public key may be freely distributed, while its paired private key must remain secret. In a public-key encryption system, the public key is used for encryption, while the private or secret key is used for decryption.

Diffie and Hellman’s publication sparked widespread academic efforts in finding a practical public-key encryption system. This race was finally won in 1978 by Ronald Rivest, Adi Shamir, and Len Adleman, whose solution has since become known as the RSA algorithm. (Rivest, Shamir, & Adleman, A Method for Obtaining Digital Signatures and Public-Key Cryptosystems, 1978)

The Diffie–Hellman and RSA algorithms, in addition to being the first publicly known examples of high quality public-key algorithms, have been among the most widely used. Other asymmetric-key algorithms include the Cramer–Shoup cryptosystem, ElGamal encryption, and various elliptic curve techniques

Credit MIT

The No figure print Techniques

Due to the fingerprint problems with the ciphertext cryptography which was based on single-key or symmetric encryption, cryptanalyst could trace clues that were used to decrypt messages. Asymmetric encryption gave the solution to the figure print problem.

Credit: MIT

A significant disadvantage of symmetric ciphers is the key management necessary to use them securely. Each distinct pair of communicating parties must, ideally, share a different key, and perhaps for each ciphertext exchanged as well. The number of keys required increases as the square of the number of network members, which very quickly requires complex key management schemes to keep them all consistent and secret.

There are a few important algorithms that have been proven secure under certain assumptions. For example, the infeasibility of factoring extremely large integers is the basis for believing that RSA is secure and some other systems, but even so proof of unbreakability is unavailable since the underlying mathematical problem remains open. In practice, these are widely used and are believed unbreakable in practice by most competent observers. There are systems similar to RSA, such as one by Michael O. Rabin that are provably secure provided factoring n = pq is impossible; it is quite unusable in practice. The discrete logarithm problem is the basis for believing some other cryptosystems are secure, and again, there are related, less practical systems that are provably secure relative to the solvability or insolvability discrete log problem (Douglas R. Stinson, 2005)

Because of the difficulty of the underlying problems, most public-key algorithms involve operations such as modular multiplication and exponentiation, which are much more computationally expensive than the techniques used in most block ciphers, especially with typical key sizes.

By: Abdul Nasir Muniru- Msc. Computer Application Technology