Java RSA private key generation when public key is known
up vote
-6
down vote
favorite
Is there a way to generate a RSA private key in java, when the public key is known, say 3 ?
I can't find a way to do this with Class KeyPairGenerator, from java.security package...
my question is very simple, I'm not looking for info related to cryptography.
Just want to know, if I have the public exponent for RSA, is there a way in java to get the private exponent, for that public exponent, for a given modulus length , e.g. 2048?
This should shed some light on the topic:
https://en.wikipedia.org/wiki/RSA_(cryptosystem)#Key_generation
https://en.wikipedia.org/wiki/65,537
java rsa key-generator
asked Nov 11 at 23:07
user2283315
12
add a comment |
up vote
-6
down vote
favorite
Is there a way to generate a RSA private key in java, when the public key is known, say 3 ?
I can't find a way to do this with Class KeyPairGenerator, from java.security package...
my question is very simple, I'm not looking for info related to cryptography.
Just want to know, if I have the public exponent for RSA, is there a way in java to get the private exponent, for that public exponent, for a given modulus length , e.g. 2048?
This should shed some light on the topic:
https://en.wikipedia.org/wiki/RSA_(cryptosystem)#Key_generation
https://en.wikipedia.org/wiki/65,537
java rsa key-generator
asked Nov 11 at 23:07
user2283315
12
what code have you tried so far ? why is it not working ? what have you searched for (libs ?)?
– LoneWanderer
Nov 11 at 23:15
An RSA public key consist and an exponent and a modulus.
– James K Polk
Nov 12 at 3:49
add a comment |
up vote
-6
down vote
favorite
up vote
-6
down vote
favorite
Is there a way to generate a RSA private key in java, when the public key is known, say 3 ?
I can't find a way to do this with Class KeyPairGenerator, from java.security package...
my question is very simple, I'm not looking for info related to cryptography.
Just want to know, if I have the public exponent for RSA, is there a way in java to get the private exponent, for that public exponent, for a given modulus length , e.g. 2048?
This should shed some light on the topic:
https://en.wikipedia.org/wiki/RSA_(cryptosystem)#Key_generation
https://en.wikipedia.org/wiki/65,537
java rsa key-generator
asked Nov 11 at 23:07
user2283315
12
Is there a way to generate a RSA private key in java, when the public key is known, say 3 ?
I can't find a way to do this with Class KeyPairGenerator, from java.security package...
my question is very simple, I'm not looking for info related to cryptography.
Just want to know, if I have the public exponent for RSA, is there a way in java to get the private exponent, for that public exponent, for a given modulus length , e.g. 2048?
This should shed some light on the topic:
https://en.wikipedia.org/wiki/RSA_(cryptosystem)#Key_generation
https://en.wikipedia.org/wiki/65,537
java rsa key-generator
java rsa key-generator
asked Nov 11 at 23:07
user2283315
12
asked Nov 11 at 23:07
user2283315
12
edited Nov 12 at 14:31
asked Nov 11 at 23:07
user2283315
12
asked Nov 11 at 23:07
user2283315
12
asked Nov 11 at 23:07
user2283315
12
12
what code have you tried so far ? why is it not working ? what have you searched for (libs ?)?
– LoneWanderer
Nov 11 at 23:15
An RSA public key consist and an exponent and a modulus.
– James K Polk
Nov 12 at 3:49
add a comment |
what code have you tried so far ? why is it not working ? what have you searched for (libs ?)?
– LoneWanderer
Nov 11 at 23:15
An RSA public key consist and an exponent and a modulus.
– James K Polk
Nov 12 at 3:49
what code have you tried so far ? why is it not working ? what have you searched for (libs ?)?
– LoneWanderer
Nov 11 at 23:15
what code have you tried so far ? why is it not working ? what have you searched for (libs ?)?
– LoneWanderer
Nov 11 at 23:15
An RSA public key consist and an exponent and a modulus.
– James K Polk
Nov 12 at 3:49
An RSA public key consist and an exponent and a modulus.
– James K Polk
Nov 12 at 3:49
add a comment |
2 Answers
2
active
oldest
votes
up vote
4
down vote
The whole point of public-key cryptography is that the private key remains secret. If there would be a way to easily generate a private key from a public key the encryption schema would be broken.
Yes, you can probably brute-force the private key but it won't be easy:
The strength of a public key cryptography system relies on the computational effort (work factor in cryptography) required to find the private key from its paired public key. Effective security only requires keeping the private key private; the public key can be openly distributed without compromising security.
answered Nov 11 at 23:21
Karol Dowbecki
15.3k82747
add a comment |
up vote
0
down vote
accepted
Sort answer is "no".
Long answer is to use sunrsasign Provider, which implements RSAKeyPairGenerator such that the public exponent is 65537:
*"/**
* RSA keypair generation. Standard algorithm, minimum key length 512 bit.
* We generate two random primes until we find two where phi is relative
* prime to the public exponent. Default exponent is 65537. It has only bit 0
* and bit 4 set, which makes it particularly efficient.
**/*
if you want a different public exponent you need to create your own provider and integrate it with JCA.
answered Nov 19 at 12:54
user2283315
12
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
4
down vote
The whole point of public-key cryptography is that the private key remains secret. If there would be a way to easily generate a private key from a public key the encryption schema would be broken.
Yes, you can probably brute-force the private key but it won't be easy:
The strength of a public key cryptography system relies on the computational effort (work factor in cryptography) required to find the private key from its paired public key. Effective security only requires keeping the private key private; the public key can be openly distributed without compromising security.
answered Nov 11 at 23:21
Karol Dowbecki
15.3k82747
add a comment |
up vote
4
down vote
The whole point of public-key cryptography is that the private key remains secret. If there would be a way to easily generate a private key from a public key the encryption schema would be broken.
Yes, you can probably brute-force the private key but it won't be easy:
The strength of a public key cryptography system relies on the computational effort (work factor in cryptography) required to find the private key from its paired public key. Effective security only requires keeping the private key private; the public key can be openly distributed without compromising security.
answered Nov 11 at 23:21
Karol Dowbecki
15.3k82747
add a comment |
up vote
4
down vote
up vote
4
down vote
The whole point of public-key cryptography is that the private key remains secret. If there would be a way to easily generate a private key from a public key the encryption schema would be broken.
Yes, you can probably brute-force the private key but it won't be easy:
The strength of a public key cryptography system relies on the computational effort (work factor in cryptography) required to find the private key from its paired public key. Effective security only requires keeping the private key private; the public key can be openly distributed without compromising security.
answered Nov 11 at 23:21
Karol Dowbecki
15.3k82747
The whole point of public-key cryptography is that the private key remains secret. If there would be a way to easily generate a private key from a public key the encryption schema would be broken.
Yes, you can probably brute-force the private key but it won't be easy:
The strength of a public key cryptography system relies on the computational effort (work factor in cryptography) required to find the private key from its paired public key. Effective security only requires keeping the private key private; the public key can be openly distributed without compromising security.
answered Nov 11 at 23:21
Karol Dowbecki
15.3k82747
answered Nov 11 at 23:21
Karol Dowbecki
15.3k82747
answered Nov 11 at 23:21
Karol Dowbecki
15.3k82747
answered Nov 11 at 23:21
Karol Dowbecki
15.3k82747
15.3k82747
add a comment |
add a comment |
up vote
0
down vote
accepted
Sort answer is "no".
Long answer is to use sunrsasign Provider, which implements RSAKeyPairGenerator such that the public exponent is 65537:
*"/**
* RSA keypair generation. Standard algorithm, minimum key length 512 bit.
* We generate two random primes until we find two where phi is relative
* prime to the public exponent. Default exponent is 65537. It has only bit 0
* and bit 4 set, which makes it particularly efficient.
**/*
if you want a different public exponent you need to create your own provider and integrate it with JCA.
answered Nov 19 at 12:54
user2283315
12
add a comment |
up vote
0
down vote
accepted
Sort answer is "no".
Long answer is to use sunrsasign Provider, which implements RSAKeyPairGenerator such that the public exponent is 65537:
*"/**
* RSA keypair generation. Standard algorithm, minimum key length 512 bit.
* We generate two random primes until we find two where phi is relative
* prime to the public exponent. Default exponent is 65537. It has only bit 0
* and bit 4 set, which makes it particularly efficient.
**/*
if you want a different public exponent you need to create your own provider and integrate it with JCA.
answered Nov 19 at 12:54
user2283315
12
add a comment |
up vote
0
down vote
accepted
up vote
0
down vote
accepted
Sort answer is "no".
Long answer is to use sunrsasign Provider, which implements RSAKeyPairGenerator such that the public exponent is 65537:
*"/**
* RSA keypair generation. Standard algorithm, minimum key length 512 bit.
* We generate two random primes until we find two where phi is relative
* prime to the public exponent. Default exponent is 65537. It has only bit 0
* and bit 4 set, which makes it particularly efficient.
**/*
if you want a different public exponent you need to create your own provider and integrate it with JCA.
answered Nov 19 at 12:54
user2283315
12
Sort answer is "no".
Long answer is to use sunrsasign Provider, which implements RSAKeyPairGenerator such that the public exponent is 65537:
*"/**
* RSA keypair generation. Standard algorithm, minimum key length 512 bit.
* We generate two random primes until we find two where phi is relative
* prime to the public exponent. Default exponent is 65537. It has only bit 0
* and bit 4 set, which makes it particularly efficient.
**/*
if you want a different public exponent you need to create your own provider and integrate it with JCA.
answered Nov 19 at 12:54
user2283315
12
answered Nov 19 at 12:54
user2283315
12
answered Nov 19 at 12:54
user2283315
12
answered Nov 19 at 12:54
user2283315
12
12
add a comment |
add a comment |
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what code have you tried so far ? why is it not working ? what have you searched for (libs ?)?
– LoneWanderer
Nov 11 at 23:15
An RSA public key consist and an exponent and a modulus.
– James K Polk
Nov 12 at 3:49