Procedures followed or measures taken to ensure the safety of something
security
We have been working with PDF files since 1999 and developed complex software to display PDF files. We have learnt a lot about the... What is a Cipher stream? Cipher streams act as streams except that they use a Cipher to process the data before it is passed... As security is an ever present issue we thought we would highlight some security features offered by the PDF file format that can be... Access to PDF files can be secured so that not just anyone can open them. This is achieved by encryption – the bytes in... 
