Every day across the internet, millions of secret messages are sent. Some might be messages from spies, but they aren’t the only people who keep secrets. For example, banks and online stores need to communicate without people stealing account details. Recently, a group of researchers discovered a problem with a popular encryption system. So what was the problem, and should we be worried?
If you want people to send you secret messages over the internet, you could make yourself an RSA key pair. RSA keys require two large prime numbers – these are usually several hundred digits long. You then multiply them together, and put this product on the internet for everyone to see. People can use this ‘public key’ to encode messages to send to you, but they can’t use it to decode those messages. Continue reading Repeated primes endanger internet codes