Security
Although dynamic memory is only specified and guaranteed to retain its contents when supplied with power and refreshed every 64 ms, the memory cell capacitors often retain their values for significantly longer, particularly at low temperatures. Under some conditions most of the data in DRAM can be recovered even if it has not been refreshed for several minutes.
This property can be used to circumvent security and recover data stored in memory and assumed to be destroyed at power-down by quickly rebooting the computer and dumping the contents of the RAM, or by cooling the chips and transferring them to a different computer. Such an attack was demonstrated to circumvent popular disk encryption systems, such as the open source TrueCrypt, Microsoft's BitLocker Drive Encryption, and Apple's FileVault. This type of attack against a computer is often called a cold boot attack.
Read more about this topic: Dynamic Random-access Memory
Famous quotes containing the word security:
“Is a Bill of Rights a security for [religious liberty]? If there were but one sect in America, a Bill of Rights would be a small protection for liberty.... Freedom derives from a multiplicity of sects, which pervade America, and which is the best and only security for religious liberty in any society. For where there is such a variety of sects, there cannot be a majority of any one sect to oppress and persecute the rest.”
—James Madison (1751–1836)
“The three great ends which a statesman ought to propose to himself in the government of a nation, are,—1. Security to possessors; 2. Facility to acquirers; and, 3. Hope to all.”
—Samuel Taylor Coleridge (1772–1834)
“If we could have any security against moods! If the profoundest prophet could be holden to his words, and the hearer who is ready to sell all and join the crusade, could have any certificate that to-morrow his prophet shall not unsay his testimony!”
—Ralph Waldo Emerson (1803–1882)