Security

Although dynamic memory is only guaranteed to retain its contents when supplied with power and refreshed every 64 ms, the memory cell capacitors will often retain their values for significantly longer, particularly at low temperatures.^[18]

Under some conditions, most of the data in DRAM can be recovered even if the DRAM has not been refreshed for several minutes.^[19]

This property can be used to recover "secure" data kept in memory 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, like the open source TrueCrypt, Microsoft's BitLocker Drive Encryption, as well as Apple's FileVault.^[18]