First used by Rivest, Shamir and Adleman, RSA is a security algorithm used in digital cryptography. RSA differs from older symmetric algorithms because it has the ability to enable digital signing and advanced encryption for e-commerce systems and high-profile institutions. RSA is now widely used to provide financial, personal, and corporate-level information security for most users.
How Does RSA Work?
The RSA key has three separate functions:
- RSA's first function is to generate both a public key and a private key. The public key is used only for encryption and can be given to anyone. The private key, however, is used for decryption and is specifically generated to work only with the public key it was created alongside. The user keeps the private key to themselves and uses it like a password to access the contents of an encrypted file.
- RSA's second function is to perform the encryption that protects files and web pages. RSA does this by selecting two random prime numbers and multiplying them in a way that produces a specific result.
- RSA's third function is to perform decryption on encrypted files using an equation that is the exact inverse of the original equation.
Applications
RSA is used specifically to allow financial institutions and other trusted organizations to show their customers that they are accessing a secure server. Online financial institutions such as banks, PayPal and MoneyBookers, online stores, and the vast majority of websites that request social security numbers or other personal information use RSA and similar encryption algorithms to protect their customers' privacy.
Advantages
There are two important reasons for using RSA:
- It allows users to electronically sign their domains and other digital information, and generally provides the ability to supply encryption for websites, servers and files.
- RSA can be used in e-mail, e-commerce and many other systems that require privacy for their users. In addition, RSA is quite complex, and decrypting it without a private key is nearly impossible.
