158
votes
Are the sticks of RAM in my desktop computer volatile? Is it safe to sell them?
Yes, they're safe. Consumer memory DIMMs use volatile SDRAM memory. Volatile means that it does not hold its state after you turn it off.
SDRAM memory chips are constructed from an array of memory ...
- 136k
110
votes
How to prevent a hosting company from accessing a VM's encryption keys?
You can't, plain and simple. If you don't trust the hosting company, you don't host with them. This is law #3 from 10 immutable law of security:
Law #3: If a bad guy has unrestricted physical ...
- 31.6k
70
votes
Are the sticks of RAM in my desktop computer volatile? Is it safe to sell them?
Yes, they’re safe to sell. No consumer PCs use non-volatile RAM for their main memory.
- 10.3k
62
votes
Emergency method to erase all data off a machine within seconds
Thermite.
Thermite burns at a temperature of thousands of degrees centigrade, which would be more than sufficient to destroy all the data stored in any modern data storage medium. It is also already ...
- 591
54
votes
Accepted
Emergency method to erase all data off a machine within seconds
There are two DEFCON videos from 2012 and 2015 exploring this exact issue:
DEFCON 19: And That's How I Lost My Eye: Exploring Emergency Data Destruction
DEFCON 23: And That's How I Lost My Other Eye.....
- 736
48
votes
Accepted
What is the benefit of having a cryptographically secure hash algorithm in hashmaps?
Sometimes applications use untrusted data as the key in a hash map. A simple implementation can allow the untrusted data to cause a denial of service attack.
Hash maps are fast - O(1) - in the best ...
- 34.7k
45
votes
Emergency method to erase all data off a machine within seconds
If you trust encryption then you could encrypt your entire drive using
Linux: LUKS (supported by all major distributions)
Windows: BitLocker
As soon as you physically switch off the device, all the ...
- 3,501
39
votes
What is the benefit of having a cryptographically secure hash algorithm in hashmaps?
Insert, search, and remove operations on hash tables have O(n) worst case behavior. If an attacker can choose keys to be inserted into a hash table and they can compute the hash function themselves ...
- 1,766
32
votes
Accepted
Is assigning decrypted keys to a variable in application secure?
Yes, it does mean that the key will be stored in the application’s memory. Yes, there is a risk that malware (with sufficient privilege) can read it from there. This risk is hard to avoid — if you ...
- 65.8k
29
votes
Should crash dumps (e.g. from Breakpad, Windows) be encrypted and signed?
Dumps give too much info for hackers to reverse engineer or hack the software, say to enable features or licenses?
The dumps must, at some point, exist in unencrypted form. An attacker with full ...
- 17.5k
29
votes
Accepted
How can two identical no-PIE binaries run simultaneously?
... it always has the same absolute base address.
No. Each process is provided by the OS with its own mapping of parts of the systems memory. The addresses in a non-PIE binary are not absolute to the ...
- 208k
28
votes
Emergency method to erase all data off a machine within seconds
A RAM disk
RAM is cool in that it is volatile memory. This essentially means that once power is cut, all data is lost completely and can never be recovered - essentially, this irreversibly and ...
- 381
19
votes
Emergency method to erase all data off a machine within seconds
Hard Drive with glass platters
HDD’s with glass platters are common. All you need to do is make sure that your data is stored on one of them, and, in an emergency, chuck it at the ground really hard. ...
- 441
18
votes
What is the benefit of having a cryptographically secure hash algorithm in hashmaps?
I agree that's a little vague and it's going to heavily depend on how the hashmaps are used.
Here's my guess: say you're taking some input from users, say [Firstname.Lastname] and using that as the ...
- 59.3k
16
votes
How to prevent a hosting company from accessing a VM's encryption keys?
so that it would not be economically viable to spend time & resources to get them.
I hate to break it to you, but you simply aren't that important. No-one knows you or your web app. So it's ...
- 845
15
votes
Accepted
How does full memory encryption in newer processes protect against DMA attacks?
How does memory encryption impact DMA attacks?
Full-memory encryption is not designed to protect against DMA attacks. That is what an IOMMU is for. The IOMMU is configured using a type of ACPI table ...
- 67.3k
14
votes
How can you detect kernel exploits?
No, there is nothing all kernel exploits have in common.
Or at least, there is nothing unique to them and not present in standard, legal interaction with the kernel (such as using syscalls or ...
- 67.3k
13
votes
How to prevent a hosting company from accessing a VM's encryption keys?
In theory, you should be able to use the trusted hardware features of modern CPUs to run your disk encryption, or even your entire VM, inside a tamper-resistant part of the CPU, having all the data on ...
- 305
13
votes
Emergency method to erase all data off a machine within seconds
The framing of this question is just completely wrong, and I'd go so far as to suggest the question doesn't belong on Security SE but Worldbuilding SE if you're trying to make up a world where it does ...
12
votes
Emergency method to erase all data off a machine within seconds
Some of HPE's SmartArray RAID controllers (for instance, the P408i) support transparent disk encryption. One of the supported configuration modes involves keys that are only ever stored in a ...
- 1,131
12
votes
Accepted
In-memory pepper
First: you are definitely correct, it can't be stored alongside your code, no secret should.
It obviously needs to be held in memory by the server since it needs to be used.
However, it can't be in-...
- 4,311
10
votes
Accepted
Does Oracle's GuardedString protect sensitive data against heap or memory dumps?
Some deeper look into the actual implementation will help an attacker understand the data structure of a memory dump, and from what I found in EncryptorImpl there has been put no effort into ...
- 340
10
votes
Accepted
How can Process Hacker view my password manager's memory without administrative rights?
Per its documentation, Process Hacker actually launches a kernel mode driver, KProcessHacker. A kernel mode driver does have access to all memory.
Sources:
https://github.com/processhacker2/...
- 1,078
10
votes
Accepted
Why is accessing kernel memory a security risk?
In order to understand the threat from Meltdown, you need to understand how memory is organized in modern computers.
The naive view of memory is that each memory address corresponds to a specific set ...
- 34.8k
9
votes
Accepted
How can I protect my home/office computer against row hammer?
The only reliable hardware mitigation that does not involve downgrading to a motherboard with DDR2 is to use memory that supports TRR (Target Row Refresh), which is optional for LPDDR4 (not the same ...
- 67.3k
9
votes
Accepted
Viewing the stack
Getting a dump of memory the simple way
You can simply send your vulnerable process a SIGSEGV (kill -SEGV pid) and, if coredump is allowed (ulimit -c unlimited), you gonna get a nice core dump file ...
- 814
8
votes
Accepted
DMA attacks despite IOMMU isolation
Recently I had been reading the papers published at the NDSSS 2019, and this paper presented in February I think answers the question completely. At the time the question was asked, it seems like the ...
- 1,065
8
votes
Emergency method to erase all data off a machine within seconds
It used to be possible to buy CPU chips with a built-in PROM that would be destroyed on contact with the atmosphere, the idea being to prevent someone from reverse engineering the code that had been ...
- 101
8
votes
Since GPUs have gigabytes of memory, does Argon2id need to use gigabytes of memory as well in order to effectively thwart GPU cracking?
Practical advice
Use Argon2id.
The more memory you use, the less of an advantage an attacker will have compared to your CPU.
In absolute numbers, against 2021 GPUs:
128 MiB is quite secure (but don'...
- 33.1k
8
votes
Accepted
What is the function of Intel's Total Memory Encryption (TME)?
Memory encryption can protect against physical attacks that exfiltrate data. The CPU and the RAM modules communicate over a bus on the motherboard. Unlike delidding the CPU and attaching probes to ...
- 1,366
Only top scored, non community-wiki answers of a minimum length are eligible