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- Proteção contra ataques cold boot
Ao usar um computador, todos os dados manipulados são escritos temporariamente na memória RAM: textos, arquivos salvos, e também senhas e chaves criptográficas. Quanto mais recente a atividade, maior é a probabilidade de que estes dados estejam na RAM.
After a computer is powered off, the data in RAM disappears rapidly, but it can remain in RAM up to several minutes after shutdown. An attacker having access to a computer before the data in RAM disappears completely could recover important data from your session.
This can be achieved using a technique called cold boot attack. To prevent such attacks, the data in RAM is overwritten by random data when you shut down Tails.
Além disso, um atacante que tenha acesso físico ao computador enquanto Tails está sendo executado também pode recuperar dados da RAM. Para evitar isto, aprenda diferentes formas de desligar o Tails rapidamente.
As far as we know, cold boot attacks are not a common procedure for data recovery.
In a research report from 2011, Defense Research and Development Canada concluded that cold boot attacks can be useful in some cases to acquire data in memory but are not a panacea and have many drawbacks dictated by the laws of physics, which cannot be overcome by the technique. The authors recommend to only use cold boot attacks as a last resort when all other avenues have been exhausted.
See how we implement this memory erasure, for example, if you want to implement this feature outside of Tails.