Solid-state drives are fast becoming popular replacements for hard drives, especially in laptops, but experts are cautioning that SSDs aren't as secure as commonly thought.

While SSDs may offer better data security than traditional hard drives, they do not completely erase data and are vulnerable to physical hacks from light sources like an ultraviolet laser, experts say. They also warn that securing data on SSDs could become a larger issue when the technology becomes more widely used and reaches other portable devices like smart phones.

Many SSDs use industry-standard NAND flash chips that were designed for cameras and MP3 players, so they have no physical security hooks that prevent them from being removed from enclosures, said Jim Handy, director of Objective Analysis, a semiconductor research and consulting firm. A hacker could easily unsolder NAND chips from an SSD and read the data using a flash chip programmer.

Once the data is read, the files could be reassembled using data recovery software, Handy said. "There's really nothing sophisticated about this process," he said.

Another physical hack involves using an ultraviolet laser to wipe out lock bits - or encryption locks - from fuses on chips that secure SSDs, said a chip hacker who prefers to be called Bunnie and runs the blog site bunnie studios. Data arrays from SSDs can be read using standard means after the lock bits are wiped.

"No fancy equipment is required to read the [data] array once it is unlocked," Bunnie said. For example, the data arrays can be read using conventional ROM readers, devices typically meant to burn and verify unsecured ROM devices.

To lessen chances of hackers stealing data, encryption keys could be integrated inside the SSD controller device to handle disk encryption at the hardware level, said Craig Rawlings, marketing director at Kilopass. Kilopass sells products using XPM (extra permanent memory) technology that stores keys in system-on-chip devices.

Encryption keys can be hacked, but experts agreed that encryption is the necessary first step to secure data on SSDs. Many companies, including Safend and Encryptx, have products that encrypt data on storage devices including SSDs.

Encryption adds another barrier so that hackers have to bypass encryption layers, the controller and then reassemble raw data for a successful hack, said Sean Barry, senior data recovery engineer at Kroll Ontrack. This takes time, during which data may become invalid or useless.

Encryption also makes files on SSDs a lot easier to erase. Like hard drives, SSDs create multiple file copies, but encryption software can help erase secured files, said Kyle Wiens, CEO of iFixIt.

"Every time you write data it might write ... to a different part of the disk and then change the directory table around. So it forgets where the data was written before," Wiens said. Users may delete one file, but a replica could remain untouched in another sector.