As SSH keys are standard asymmetrical keys we can use the tool to create keys for other purposes. The -t option specifies the key generation algorithm RSA in this case , while the -b option specifies the length of the key in bits.
The -f option sets the name of the output file. The tool always asks for a password to encrypt the key, but you are allowed to enter an empty one to skip the encryption.
This tool creates two files. One is the private key file, named as requested, and the second is the public key file, named like the private key one but with a. The public key saved by ssh-keygen is written in the so-called SSH-format, which is not a standard in the cryptography world. The structure of this binary file is pretty simple, and is described in two different RFCs.
This means that the above sequence of bytes is interpreted as 4 bytes of length 32 bits of the uint32 type followed by that number of bytes of content. Please note that since we created a key of bits we should have a modulus of bytes. Instead this key uses bytes prefixing the number with a 00 byte to avoid it being interpreted as negative two's complement format.
This string, converted in Base64 gives the initial 9 bytes 00 00 00 07 73 73 68 2d 72 Base64 characters are not a one-to-one mapping of the source bytes. We often need to convert files created with one tool to a different format, so this is a list of the most common conversions you might need.
I prefer to consider the key format instead of the source tool, but I give a short description of the reason why you should want to perform the conversion.
Now you can hopefully understand the documentation that says. This instance contains the RSA parameters as attributes as stated in the documentation. I keep finding on StackOverflow and on other boards messages of users that are confused by RSA keys, the output of the various tools, and by the subtle but important differences between the formats, so I hope this post helped you to get a better understanding of the matter.
Instagram Ads in Which Perform Better? Interview Decentralized Interview. Site Color. Ad Color. Sign Up to Save Your Colors. Privacy Terms. The most widely accepted storage format is called PEM. Leetham connected to the faraway Rackspace machine and typed in the stolen credentials. Using hacked credentials to log into a server that belongs to another company and mess with the data stored there is, Leetham admits, an unorthodox move at best—and a violation of US hacking laws at worst.
It was empty. This content can also be viewed on the site it originates from. The RSA breach, when it became public days later, would redefine the cybersecurity landscape. Timo Hirvonen, a researcher at security firm F-Secure, which published an outside analysis of the breach , saw it as a disturbing demonstration of the growing threat posed by a new class of state-sponsored hackers.
The question was quite literal. RSA's SecurID tokens were designed so that institutions from banks to the Pentagon could demand a second form of authentication from their employees and customers beyond a username and password—something physical in their pocket that they could prove they possessed, thus proving their identity. Only after typing in the code that appeared on their SecurID token a code that typically changed every 60 seconds could they gain access to their account.
RSA had added an extra, unique padlock to millions of doors around the internet, and these hackers now potentially knew the combination to every one. The Kremlin operatives who hacked SolarWinds hid espionage code in an IT management tool called Orion, used by as many as 18, companies and institutions globally.
For those with a longer memory, though, the RSA breach was the original massive supply chain attack. Now those agreements have expired, allowing them to tell me their stories in new detail. After 10 years of rampant state-sponsored hacking and supply chain hijacks, the RSA breach can now be seen as the herald of our current era of digital insecurity—and a lesson about how a determined adversary can undermine the things we trust most.
A technical director investigating the anomalous login with Leetham and the admin asked Bill Duane, a veteran RSA engineer, to take a look. To Duane, who was busy working on a cryptographic algorithm at the time, the anomaly hardly looked like cause for alarm. The admin had been right. The RSA staffers began putting in nearly hour workdays, driven by the chilling knowledge that the breach they were tracking was still unfolding.
Management demanded updates on their findings every four hours, day or night. He'd opened it. But it was from this ingress that the RSA analysts say the intruders began to demonstrate their real abilities. Today that credential-stealing hopscotching technique is common.
But in the analysts were surprised to see how the hackers fanned out across the network. Breaches as extensive as the one carried out against RSA are often discovered months after the fact, when the intruders are long gone or lying dormant.
But Duane says that the incident was different: Within days, the investigators had essentially caught up to the intruders and were watching them in action. It was in the midst of that feverish chase that Leetham caught the hackers stealing what he still believes was their highest-priority target: the SecurID seeds.
Every 15 minutes, that server would pull off a certain number of seeds so that they could be encrypted, written to a CD, and given to SecurID customers. Now, instead of the usual once-everyminutes connections, Leetham saw logs of thousands of continuous requests for data every second. These developments may leave people feeling a little bit naked if they have to use a shorter bit key for any of the reasons suggested above e. It has also resulted in some people spending time looking for bit smart cards and compatible readers when they may be better off just using bits and investing their time in other security improvements.
In fact, the "risk" of using only rather than bits in the smartcard may well be far outweighed by the benefits of hardware security especially if a smartcard reader with pin-pad is used. My own conclusion is that is not a dead duck and using this key length remains a valid decision and is very likely to remain so for the next 5 years at least.
The US NIST makes a similar recommendation and suggests it will be safe until , although it is the minimum key length they have recommended. My feeling is that the Debian preference for bit PGP keys is not based solely on security, rather, it is also influenced by the fact that Debian is a project run by volunteers. Given this background, there is a perception that if everybody migrates from to , then there would be another big migration effort to move all users from to and that those two migrations could be combined into a single effort going directly from to , reducing the future workload of the volunteers who maintain the keyrings.
This is a completely rational decision for administrative reasons, but it is not a decision that questions the security of using bit keys today. Therefore, people should not see Debian's preference to use bit keys as a hint that bit keys are fundamentally flawed. Unlike the Debian keys which are user keys , the CACert.
Therefore, the choice of using or is not pre-determined, and it can be balanced with a range of other decisions:.
RSA Key Sizes: or bits? The discussion here is exclusively about RSA key pairs, although the concepts are similar for other algorithms although key lengths are not equivalent The case for using bits instead of bits Some hardware many smart cards, some card readers, and some other devices such as Polycom phones don't support anything bigger than bits. Uses less CPU than a longer key during encryption and authentication Using less CPU means using less battery drain important for mobile devices Uses less storage space: while not an issue on disk, this can be an issue in small devices like smart cards that measure their RAM in kilobytes rather than gigabytes So in certain situations, there are some clear benefits of using bit keys and not just jumping on the bit key bandwagon The case for using bits If an attack is found that allows a bit key to be hacked in hours, that does not imply that a bit key can be hacked in hours.
The hack that breaks a bit key in hours may still need many years to crack a single bit key. It is also worth noting that simply adding 1 bit going from bits to bits does not double the effort to crack the key, each extra bit adds some security but a little bit less than what was gained with the previous bit.
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