RSA is used for public KEY cryptography. That is, it is a way of sending a message to someone where ONLY that person can read the message. This is called asymmetric cryptography. Symmetric cryptography is where two people (or computers) know the same secret and can use it to send and receive data. Asymmetric is one way, symmetric is two ways.
This is used in computer networks to verify the identity of computers or people because they have the secret "private" key that matches the "public" key everyone else has. You can prove this with math, and it is extremely hard (most people would say "impossible") to fake a private key.
Usually asymmetric cryptography is used for two machines / people to verify each other's identity, then to send a temporary key for symmetric cryptographic algorithms (known as a "session key").
Most secure protocols on the internet (SSL, TLS, IPSEC) use this method to secure data.
This is used in computer networks to verify the identity of computers or people because they have the secret "private" key that matches the "public" key everyone else has. You can prove this with math, and it is extremely hard (most people would say "impossible") to fake a private key.
Usually asymmetric cryptography is used for two machines / people to verify each other's identity, then to send a temporary key for symmetric cryptographic algorithms (known as a "session key").
Most secure protocols on the internet (SSL, TLS, IPSEC) use this method to secure data.