Encryption is used by many to protect their data, but as technology increases in power it may not be as secure as you think. Most encryption schemes use large numbers that are easy to calculate if you know their two prime factors. However, without that knowledge, brute force attacks and extensive CPU time are necessary to break the encryption. Researchers have used a cluster to crack an encryption key for 768-bit RSA encryption. The calculations would have taken a 2.2GHz Opteron processor 1,500 years. The data obtained was 5TB in size. Casual users should still be safe, as the only organizations with these kinds of resources likely have bigger issues to worry about.