The use of cryptography is safeguarding information and communications by the use of code, to ensure that only those who the information is meant can access and read it.
In the field of computer science and technology cryptography is a term used to describe security-based information and communication methods which are derived from mathematical ideas and the use of rules-based calculations , also known as algorithms, that alter messages in ways that are difficult to understand.
These algorithms that are deterministic are utilized to generate cryptographic keys digital signing, verification to safeguard privacy of data and web browsing on the internet, and for sensitive communications like credit card transactions as well as email.
Cryptography techniques
The field of cryptography is closely linked to the fields in Cryptology as well as the field of cryptanalysis. It encompasses techniques like microdots, combining words with images, and various other methods to conceal information from storage or in transit.
In the modern computer-driven society, cryptography commonly associated with scrambling plaintext (ordinary text, often called cleartext) into encrypted text (a method known as encryption) before reversing it (known by the term decryption). People who are experts in this area are known as cryptographers.
Modern cryptography has the following four goals:
- The information cannot be read by any person who was not intended to.
- The information cannot be changed in storage or during transfer between the sender and the intended recipient without being discovered.
- No-repudiation. The creator/sender of the information can not be able to deny later their intentions when it comes to the creation or transmitting the information.
- The sender and recipient can verify their identities and also the source and destination of the data.
Methods and protocols that meet one or more of these criteria are referred to as cryptosystems. The term “cryptosystems” is often used to be referring to computer programs and mathematical processes but they also encompass the regulation that governs human behaviour, for example, selecting passwords that are difficult to guess, locking off unneeded systems, and not discussing sensitive processes with strangers.
The process of cryptography involves encryption and decrypting data.
Algorithms for cryptography
Cryptosystems employ a series of processes referred to as cryptographic algorithms, also known as cryptographic ciphers which are used to decrypt and decrypt messages in order to protect communications between computers devices, devices and applications.
A cipher suite employs an encryption algorithm while another algorithm is used for authentication of messages, and a third to exchange keys. This procedure, which is embedded into protocols and implemented in software running within operating system (OSes) as well as networked computer systems, include:
- public & private key generation for encryption
- Key exchange
Cryptography types
Single-key encryption or symmetric-key algorithms produce a set number of bits, also known as a block-cipher. The cipher is comprised of an encryption key that the creator or sender uses to encrypt information (encryption) and then the receiver utilizes to decipher the data.
A good example of symmetric-key cryptography can be found in that of the Advanced Encryption Standard ( AES). AES is a standard that was established at the end of November in 2001 by National Institute of Standards and Technology (NIST) as an Federal Information Processing Standard (FIPS 197) to safeguard sensitive data.
As of June 3, 2003 AES had been passed from The U.S. government for classified information. It is a free, royalty-free specification that is used in hardware and software across the globe. AES is the successor of the Data Encryption Standard ( DES) and DES3. It utilizes longer length keys (128-bit, the 192-bit and 256-bit keys to protect against brute force and other attacks.
Symmetric cryptography utilizes only one key while the asymmetric cryptography system uses an encryption key pair that can encrypt the data and then decrypt it.
The public-key, also known as Asymmetric-key encryption algorithms employ a pair keys: a public key belonging to the creator/sender encryption of messages, and the private key only the creator/sender has access to (unless it’s disclosed or they opt to disclose the key) to decrypt the information.
Examples of cryptography with public keys include:
- RSA extensively used on the internet
- Digital Signature Algorithm (DSA) was adopted as an Federal Information Processing Standard for digital signatures by NIST in FIPS 186-4
- Diffie-Hellman key exchange
To guarantee integrity of cryptography data, hash functions are used to ensure data integrity. They provide a predictable output from input values can be used to map data to a predetermined size. The types of cryptographic hash functions are SHA-1 (Secure Hash Algorithm 1)), SHA-2 and SHA-3.
Concerns about cryptography
Hackers are able to overcome cryptography, hack into the computers responsible for encryption of data and decryption, and also exploit weak implementations, like using default key encryption. However, the use of cryptography makes it more difficult for hackers to gain access to data and messages secured with encryption techniques.
Concerns about the quantum computing power that can be used for processing computing that may breach existing encryption standards in cryptography caused NIST to release an invitation to submit papers to the scientific and mathematical community in 2016 to develop new public key encryption standards.
In contrast to the current computers quantum computing makes use of quantum bits ( qubits) that are able to represent both 1s and 0s and thus simultaneously perform two calculations.
While a huge-scale quantum computer could not be constructed within the next decade however, the current infrastructure needs the creation of a standardization process for widely known algorithms that can provide security according to NIST. Deadline for submissions came in November 2017. The analysis of the submissions will take anywhere from up to three years.
The history of cryptography
The term “cryptography” originates in the Greek “kryptos,” meaning hidden. which means hidden.
The prefix “crypt–” refers to “hidden” as well as “vault,” and the suffix “-graphy” is a reference to “writing.”
The history of cryptography can be generally dated around the year 2000 B.C., with the Egyptian practice of hieroglyphics. They consisted of complicated pictograms, the complete significance of which was only understood by the elite small group of people.
The first time that we have heard of an advanced cipher was by Julius Caesar (100 B.C. up to 44 B.C. ) and was not a fan of his messengers in communicating with his officers and governors. To avoid this, the man devised a system the sense that each letter of his message was substituted with an alphabet three places ahead from it within the Roman alphabet.
In recent years it has been transformed into a battlefield for the best mathematicians and computer researchers. Securely storing as well as move sensitive data has proven to be to be a crucial factor in business and war.
Since governments don’t wish for certain organizations in and outside of their country to be able to obtain and transmit information that could pose an affront to national security and security, cryptography is subject to a variety of restrictions in a variety of countries, from the limitations on the use or exportation of computer software, to diffusion mathematics that can be used in the development of cryptosystems.
But, the internet has enabled the dissemination of powerful software and, most importantly, the fundamental algorithms of cryptography, so that today , many of the most sophisticated cryptosystems and concepts are accessible to the public.
