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What can only be encrypted with a public key and decrypted with a private key?
Wiki User
∙ 13y ago
When one key is used for encryption and a different key is used for decryption this is call asymmetric cryptography. A good example of this is PGP (pretty good privacy). PGP is used to secure email. It accomplishes this by generating a pair of keys for each user. After the keys have been generated each user shares one key their public key and keeps their privet key secret. When someone wants to email a person who is using PGP they encrypt their message with the recipient's public key. This ensures that the message cannot be snooped on during transit and that only the person who has the corresponding privet key can decrypt the message.
Wiki User
∙ 13y ago
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How do you decrypt a data file to that has been encrypted with the users public key?
When you reference a "public key" you are implying that the file has been encrypted using "asymmetric cryptography". In asymmetric cryptography, encryption and decryption depend on a key PAIR. The user retains their private key and publishes their public key. Anyone can encrypt a file using the user's public key and send it to them. The only person who should be able to decrypt a file encrypted with that public key is the holder of the private key - which, unless the user has made the mistake of sharing their private key - means that only the original user can decrypt the messages sent to them. Most of the asymmetric encryption algorithms use pretty much the same method to decrypt that was used to encrypt, but use the "other" key from the key pair. Messages encrypted using the private key can only be decrypted using the public key - which provides some authentication that the message indeed came from the holder of the private key. Messages encrypted using the public key can only be decrypted by the holder of the private key, so messages sent to them should be secure.
Where can you decrypt Public Key Cryptography?
Public key cryptography always works the same way: Encryption is done with the public key, decryption done with the private key. It is not possible to decrypt anything with the public key (otherwise the whole system would crash down). The only time it's done the other way is for message authentication, where only a digest of a message is encrypted and can be verified (not decrypted) using the public key.
How does asymmetric encryption provide confidentiality?
Asymmetric encryption can provide confidentiality in two ways:1) messages encrypted using the public key of the recipient can only be decrypted using the private key of the recipient - which only the recipient should possess.2) It can be used as part of a negotiation process between two users to establish a temporary shared key through a process such as the following:User A sends a challenge message to user B which is encrypted with user B's public key to initiate secure communications.User B decrypts the message and sends the correct response back to user A encrypted with user A's public keyThe two users are now authenticated to each otherAt this point A can send a proposed symmetric key to B encrypted with B's private keyAll further communications are encrypted via the shared symmetric keyIn this second scenario, the asymmetric encryption only facilitates the establishment of confidentiality via the eventually shared symmetric key by securing the initial negotiations.
In asymmetric encryption Both the sender and receiver have a private key and a shared private key?
No, both sender and receiver have a private key and a public key. It works like this: if you encrypt something with one key, you need the other to decrypt it. You give everyone a copy of your public key. When they want to send you something encrypted, they use your public key to send it. Only your private key can decrypt it, so no one else can read it. You don't give out your private key.
Access denied encrypted files?
Encrypted files can only be accessed by authorized computer users who have the decryption key. Encryption is a popular technique in Information Security.
Utilizing Public Key Encryption How would John and Jim send an encrypted message between parties?
John would use Jim's public key to encrypt and Jim would use his private key to decrypt.Public Key Cryptography (Asymmetric encryption)An algorithm where data encrypted with a public key can only be decrypted by the matching private key. Vice versa is true, what is encrypted with a private key can only be decrypted with a public key.
How do you decrypt a data file to that has been encrypted with the users public key?
When you reference a "public key" you are implying that the file has been encrypted using "asymmetric cryptography". In asymmetric cryptography, encryption and decryption depend on a key PAIR. The user retains their private key and publishes their public key. Anyone can encrypt a file using the user's public key and send it to them. The only person who should be able to decrypt a file encrypted with that public key is the holder of the private key - which, unless the user has made the mistake of sharing their private key - means that only the original user can decrypt the messages sent to them. Most of the asymmetric encryption algorithms use pretty much the same method to decrypt that was used to encrypt, but use the "other" key from the key pair. Messages encrypted using the private key can only be decrypted using the public key - which provides some authentication that the message indeed came from the holder of the private key. Messages encrypted using the public key can only be decrypted by the holder of the private key, so messages sent to them should be secure.
What is a characteristic of public key cryptography?
If data is encrypted with the public key, only the private key can decrypt itAnswer Explanation: Public key encryption uses an asymmetric algorithm, which uses a public key and private key combination for the encryption and decryption process. If data is encrypted with the public key, only the private key can decrypt the data. The public key cannot decrypt a message that was encrypted with the public key. Alternatively, if data is encrypted with the private key, only the public key can decrypt the data.
What are characteristics of public key cryptography?
If data is encrypted with public key, only private key can decrypt it. AGN
How many keys are utilized in asymmetric encryption?
Asymmetric encryption uses at least 2 keys - hence the asymmetry. The keys for encryption and decryption are not the same, so they are not "symmetric". Usually only 2 keys are used - a public key and a private key. The public key is published to a key registry or sent separately to those the key-pair owner wants to communicate with. The private key is retained by the owner. Messages encrypted with the private key can only be decrypted using the public key. If the source of the public key is trusted, this provides some proof of the source of the message. Messages encrypted with the public key can only be decrypted using the private key - so only the owner of the private key should be able to decrypt messages encrypted with their own private key.
What are the roles of Public and Private Key?
A user's private key is kept private and known only to the user. The user's public key is made available to others to use. The private key can be used to encrypt a signature that can be verified by anyone with the public key. Or the public key can be used to encrypt information that can only be decrypted by the possessor of the private key
Where can you decrypt Public Key Cryptography?
Public key cryptography always works the same way: Encryption is done with the public key, decryption done with the private key. It is not possible to decrypt anything with the public key (otherwise the whole system would crash down). The only time it's done the other way is for message authentication, where only a digest of a message is encrypted and can be verified (not decrypted) using the public key.
What is The essential ingredients of asymmetric cipher?
Symmetric ciphers use only one key. By contrast, an asymmetric cipher will use two keys. One key is kept "private" by the the owner while the other is "published" or otherwise released to the public (hence known as the "public key"). Data encrypted by one key can only be decrypted using the other key.
Is there a need of physical security while using cryptography?
Yes. Decrypted or plain text - yet to be encrypted - messages need to be kept securely before they are encrypted and transmitted.
What is difference between secret key and public key encryption?
It depends on how you apply the term "secret key encryption". In one sense "Secret key encryption" refers to using symmetric keys - both parties have the key and must keep it secret in order to protect the confidentiality of the communication. Usually the process that was used to encrypt the original message can be decrypted by repeating the encryption process with the original secret key. This should provide for confidentiality, non-repudiation, and validation since only the holders of the shared secret key should be able to successfully encrypt and decrypt the messages. In contrast to the symmetric key encryption, Public Key encryption uses two keys in the encryption/decryption process. Anything encrypted with one key can be decrypted with the other key. The "public key" is published for everyone to access. The "private key" is kept by the owner and not made available to the world. The encryption of the original message using one key can be "undone" only by using the other key. Using the public key on a message already encrypted with the public key only results in an even more jumbled and unintelligible mess. The end result is that is someone encrypts a message with their private key, only their public key can be used to decrypt it, thus verifying the source of the message. Any message encrypted using the public key can only be decrypted with the private key, thus providing confidentiality. If two users want to use asymmetric encryption to communicate securely, they can do it this way: Alice encrypts a message to Bob using Bob's public key. Only Bob can decrypt it and read it (using his private key). He can then send a return email to Alice using Alice's public key that only Alice can decrypt and read (using her own private key). If they wish, they can use this method to agree upon and exchange a shared symmetric key than can be used for further secure communications. Several automatic secure protocols use exactly this method or a variation of it. The alternate meaning is to make "secret key" synonymous with the "private key" of asymmetric encryption. In this case there is really no difference between secret key and public key encryption except for which key of the public/private key pair is being used and who can read it.
What are public keys and private keys in networking?
The Public and Private key pair comprise of two uniquely related cryptographic keys (basically long random numbers). Below is an example of a Public Key: 3048 0241 00C9 18FA CF8D EB2D EFD5 FD37 89B9 E069 EA97 FC20 5E35 F577 EE31 C4FB C6E4 4811 7D86 BC8F BAFA 362F 922B F01B 2F40 C744 2654 C0DD 2881 D673 CA2B 4003 C266 E2CD CB02 0301 0001 The Public Key is what its name suggests - Public. It is made available to everyone via a publicly accessible repository or directory. On the other hand, the Private Key must remain confidential to its respective owner. Because the key pair is mathematically related, whatever is encrypted with a Public Key may only be decrypted by its corresponding Private Key and vice versa. For example, if Bob wants to send sensitive data to Alice, and wants to be sure that only Alice may be able to read it, he will encrypt the data with Alice's Public Key. Only Alice has access to her corresponding Private Key and as a result is the only person with the capability of decrypting the encrypted data back into its original form.
How does asymmetric encryption provide confidentiality?
Asymmetric encryption can provide confidentiality in two ways:1) messages encrypted using the public key of the recipient can only be decrypted using the private key of the recipient - which only the recipient should possess.2) It can be used as part of a negotiation process between two users to establish a temporary shared key through a process such as the following:User A sends a challenge message to user B which is encrypted with user B's public key to initiate secure communications.User B decrypts the message and sends the correct response back to user A encrypted with user A's public keyThe two users are now authenticated to each otherAt this point A can send a proposed symmetric key to B encrypted with B's private keyAll further communications are encrypted via the shared symmetric keyIn this second scenario, the asymmetric encryption only facilitates the establishment of confidentiality via the eventually shared symmetric key by securing the initial negotiations.
