With the dawn of e-commerce, a crucial question loomed: how could users trust the identity of entities lurking on the other side of the digital divide? In the Wild West days of the early internet, this question remained largely unanswered. Yet, as the years unfolded, a powerful safeguard emerged: the shield of 256-bit encryption.
What is 256-Bit Encryption?
256-bit encryption refers to an encryption method where the key used to encrypt and decrypt data or files is 256 bits long. This length makes the key incredibly secure, as it can generate more than 2^256 combinations (over 1.1 x 10^77) - a number so large that even the fastest computers cannot feasibly crack it. Commonly used in sophisticated encryption algorithms like AES and SSL, '256-bit' signifies the size of the key that both encrypts and decrypts the information. Each key is made up of 256 binary bits, or a sequence of 1s and 0s, which provides a high level of complexity and security. This military-grade encryption is trusted worldwide by governments, financial institutions, and advanced security systems to protect highly sensitive data, ensuring maximum protection against hacking and unauthorized access.
Imagine a bustling digital marketplace, where sensitive information like credit card numbers and personal details dance across invisible wires. 256-bit encryption acts as a fortress, cloaking this data in code with over 2^256 possible combinations – a number so vast that even the most potent supercomputers would struggle to crack it for eons.
Think of it like a bank vault guarded by a colossal, 256-digit padlock. Each digit, a single bit (either 0 or 1), contributes to the lock's unyielding complexity. Cracking such a code would require brute-forcing every possible combination – a monumental task akin to searching for a grain of sand on a cosmic beach.
This robust encryption method isn't just a theoretical marvel; it's the backbone of secure online transactions. From online banking to e-commerce giants, 256-bit encryption stands as a silent sentinel, safeguarding our digital lives with every click and swipe.
Public Key Infrastructure to the Rescue!
This solution emerged through public key infrastructure (PKI), a framework outlining how to use public key encryption for authenticating participants in web transactions. Central to PKI are two types of keys: the public key, which is widely accessible, and the private key, kept confidential by its owner. These keys function in tandem, allowing one to use a public key to confirm that a message was indeed sent by the holder of the corresponding private key. Additionally, PKI facilitates asymmetric encryption, where a message encrypted with a public key can only be decrypted by someone with the matching private key.T
Public and private keys meet in what are known as digital signatures. These coded messages abide by public key infrastructure which enables signers to use their private keys to create the digital signature. The mathematical algorithm underlying the private key creates a hash and encrypts the data, thereby producing a digital signature.
Electronic signature technology provider Docusign provides an example of how digital signatures can help authenticate an individual involved in a transaction:
"… Jane signs an agreement to sell a timeshare using her private key. The buyer receives the document. The buyer who receives the document also receives a copy of Jane’s public key. If the public key can’t decrypt the signature (via the cipher from which the keys were created), it means the signature isn’t Jane’s, or has been changed since it was signed. The signature is then considered invalid."
It's imperative that parties can ensure the integrity of a digital signature. As a result, public key infrastructure frequently requires the sender of a document and the recipient to agree on using reputable Certificate Authorities (CAs) for creating, conducting, and saving their asymmetric keys. A type of service provider, CAs are third-party organizations that help ensure key security. They're responsible for issuing security certificates, electronic documents which contain a digital signature's public key and the identity associated with that key. Security certificates therefore help confirm the owner of a public key and are essential to creating a digital signature.
Security certificates don't last forever; CAs issue them for a specified period of time and then require owners to renew them. Once issued, these certificates appear in security certificate management systems and tie into the central directory, a repository of stored and indexed keys maintained by the public key infrastructure. If a CA has any reason to revoke a security certificate before it reaches its expiration, that document likely ends up in a certificate revocation list (CRLs). Browsers can use this list to not trust revoked security certificates, thereby protecting web users against bad actors who might seek to abuse expired/revoked security certificates.
The Evolution of Security Certificates
Security certificates come in many different forms. Most commonly, an organization purchases a security certificate and installs it on a web server. Doing so authenticates the identity of the website for web browsers and visitors as well as encrypts data transmitted between the website and the visitor.
To establish these secure communication channels, domain owners often obtain Secure Sockets Layer (SSL) security certificates. Netscape Communications originally developed SSL in 1994, which means it's most likely the first cryptographic protocol developed for the Internet. Today, SSL helps secure emails sent using the Simple Mail Transfer Protocol (SMTP), phone calls placed via the Voice over Internet Protocol (VoIP), files exchanged over the File Transfer Protocol (FTP), and processes that make use of other protocols. Of course, it also works with the Hypertext Transfer Protocol (HTTP) to produce Hypertext Transfer Protocol Secure (HTTPS), which establishes encrypted communications on the web.
The most recent version of Secure Sockets Layer is SSL 3.0. As internet security requirements became more sophisticated, SSL evolved into a more advanced and secure version known as TLS. The change in name from SSL to TLS occurred with the release of TLS 1.0 in 1999, which was an upgrade of SSL 3.0. This shift not only marked improvements in security features and encryption methods but also signified the protocol's standardization and adoption by the Internet Engineering Task Force (IETF). Today, TLS is widely recognized as the standard protocol for secure internet communication, replacing SSL in most applications.This successor protocol's latest version is TLS 1.3.
AES: Its Key Sizes and Role in 256-Bit Encryption
Underlying the actual data transmission of SSL and TLS is the Advanced Encryption Standard (AES). A successor of the Data Encryption Standard (DES), AES is an encryption standard technique used by many cryptographic libraries. Organizations traditionally use AES for symmetric key cryptography, or use of the same key to encrypt and decrypt messages.
AES candidates support a fixed block length of 126 bits. But the standard supports three key lengths: 128 bits, 192 bits, and 256 bits. Most organizations require their employees to use AES 256-bit encryption because of the 2256 possible key combinations that a brute force attacker would need to try in order to guess the key.
To put things into perspective, it would take one billion billion years to crack a 128-bit key. This is already older than the age of the universe (13.82 billion years) and is therefore considered uncrackable. 256-bit encryption keys, by comparison, require 2128 times the computational power needed to break a 128-bit key. This size considerably raises the stakes of cracking a 256-bit encryption key. Using a hypothetical scenario provided by Wikipedia, say 50 supercomputers have the ability to try one billion billion key combinations each second. It would still take them 3×1051 years to exhaust the key space under 256-bit encryption.
Digital Certificates, Keys, and Machine Identities
Security certificates and 256-bit encryption keys managed by the public key infrastructure all constitute machine identities. These capabilities enable authentication and encryption for security protocols like SSL and TLS. But if not adequately protected, digital attackers could abuse them to target an organization's IT infrastructure. Indeed, attackers could abuse access to machine identities to steal trusted credentials and thereby bypass other security controls. Attackers could then steal private (including 256-bit encryption) keys, forge security certificates, compromise Certificate Authorities (CAs), leverage encrypted tunnels, and exploit machine identities to steal data and/or conduct digital espionage.
Machine identities are high-value targets for digital attackers and malicious insiders. Acknowledging this risk, organizations need to strengthen their machine identity management infrastructure. This effort begins with gaining global visibility into all certificates and keys used in internal and external infrastructures, the cloud, and other environments.