Exam papers have been tagged and other new technology has been used for the first time to try to combat cheating.
Last year, Edexcel investigated 70 suspected security breaches
Exam board Edexcel is trying new ways to tighten security to deter cheats and detect fraudulent activity in its GCSE and A-level papers.
A joint exams body already polices the system, with schools following strict procedures to maintain security.
But papers do go missing. Some are stolen and sold. Others have been distributed on the internet.
Teacher Farzana Akbar was given a three-month sentence and was banned from teaching for three months after admitting taking five GCSE maths papers from the Archbishop Lanfranc School in south London in 2002.
And in 2004, police were called in to investigate the theft of maths and chemistry A-level papers, after questions were posted on a website ahead of the exam.
The exam boards work together against cheats through the Joint Council for Qualifications, which sends out compliance officers to check on each school and college.
There are strict guidelines governing how papers are stored in colleges or schools (in locked cupboards in a room locked by examinations officers) and how soon before an exam the packages can be undone.
Edexcel is trying out extra security methods at an unknown number of exam centres.
Contents of exam papers boxes can be checked easily
Radio frequency tags such as those used on clothes and CDs in shops are being put on each bundle of exam papers. The tags will store data such as how many papers are in the bundle, where they came from and where they are going.
They will not be tracked remotely, but instead will speed up checks carried out by compliance officers. Edexcel says it will be easier to spot if a package has been tampered with.
The second use of new technology involves what is called micro-texting.
A distinctive printing technique is used so that a paper which was photocopied could be easily identified.
Certain tiny marks would not be seen on a photocopy and would only be visible under a magnifying glass on a genuine paper.
The other side of the anti-cheating drive relates to the detection of students who might have cheated.
Edexcel says it is using technology which will spot students who get unexpectedly high results if they have already taken modules for the same exam.
This would prompt further investigation, it says.
Last year Edexcel delivered 620,000 bags of papers to schools and colleges.
It investigated 70 suspected security breaches, the majority of which involved packages that had been inadvertently opened at the wrong time.
Edexcel's managing director, Jerry Jarvis said: "Incidents involving stolen papers are extremely rare, but the potential impact is massive.
"The logistics of re-issuing an alternative paper to schools and colleges around the country and re-training markers on the new paper are complicated, costly and could ultimately be detrimental to candidates.
"We're doing a major trial of new techniques and technologies with the aim of deterring potential thefts, enabling us to better identify the source of a lost or stolen paper, and reducing the threat of fake papers being sold to candidates."
The exam board is also working on the development of lockable security boxes which could be unlocked by mobile phone communications or by secure password.
Centres would be unable to access papers until a specified time before the exam.
Edexcel says this technology would be aimed at centres with a known risk for insecure storage.