data encryption
TRANSCRIPT
Data Encryption
Presented By:
Deepam Goyal
Department of Mechanical Engineering
UIET, Panjab University Chandigarh
Data Encryption Encryption Definition:
The action of disguising information so that it can be recoveredeasily by the persons who have the key, but is highly resistant torecovery by persons who do not have the key.
encryption is the process of transforming information (referred to as plaintext) using an algorithm (called cipher) to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key
Data Encryption
The encryption key may be changed from time to timeto make an intruder’s task more difficult.
Restoration of a ciphertext to cleartext is achieved by theaction of decryption using a decryption key.
Data Encryption A message is cleartext (plaintext) is encrypted
(disguised) through the use of an encryption key tocreate a Ciphertext.
Data Encryption
In symmetric (Single key):
The encryption and decryption keys are the same.
In asymmetric (two keys):
The encryption and decryption keys are different.
Comparison of Symmetrical and
Asymmetrical Cryptography
Data Encryption Encryption Methods:
Encryption is accomplished by scrambling the bits,characters, words, or phrases in the original message.Scrambling involves two activities:
Transposition
Substitution
Data Encryption Transposition:
In which the order of the bits patterns, characters, words or phrases is rearranged.
The word “hello” can be written backwards as “OLLEH”.
Substitution:
In which new bit patterns, characters, words, or phrasesare substituted for the originals without changing theirorder.
Data Encryption Data Encryption Standard (DES):
Most widely used algorithm
Pioneered by IBM
It is symmetric cryptosystem
Developed to protect sensitive, unclassified, US government, Computer data.
Used to provide authentication of electronic funds transfer messages.
Why encrypt? Protect data even in the event of a security breach
Safeguard patient information
HIPAA compliance, and
TO AVOID
Financial loss (large fines, lost patients & revenue)
Legal ramifications (regulatory or civil prosecution)
Damage to professional image (negative publicity & media fallout)
Data EncryptionDES Algorithm:
The algorithm accepts plaintext, P, and performs aninitial permutation, IP, on P producing P0, The block isthen broken into left and right halves, the Left (L0)being the first 32 bits of P0 and the right (R0) being thelast 32 bits of P0.
With L0 and R0, 16 rounds are performed until L16 andR16 are generated.
The inverse permutation, IP-1, is applied to L16R16 toproduce ciphertext C.
Data Encryption Public Key Cryptosystem
It is an asymmetric cryptosystem.
First announced in 1976.
Offer a radically different approach to encryption.
The idea depends on the use of a pair of keys that differ in a complementary way.
Several algorithms are proposed
RSA algorithm is considered to be highly secure.
Data Encryption Public key encryption can achieved:
Privacy
Authentication
MEANING
A digital signature is an electronic signature that can be used to authenticate the identity of the sender of a message or the signer of a document, and possibly to ensure that the original content of the message or document that has been sent is unchanged.
Digital signatures are easily transportable, cannot be imitated by someone else, and can be automatically time-stamped. The ability to ensure that the original signed message arrived means that the sender cannot easily repudiate it later.
A digital signature can be used with any kind of message, whether it is encrypted or not, simply so that the receiver can be sure of the sender's identity and that the message arrived intact. A digital certificate contains the digital signature of the certificate-issuing authority so that anyone can verify that the certificate is real.
HOW IT WORKSOriginal message
Hash function
Sender’s private key
Cipher text(including hash digest)
Sender’s public key
Recipient’s private key
Hash
receiver
Creating a Digital Signature
Hash
Function
Jrf843kjfgf*£$&Hdi
f*7oUsd*&@:<CH
DFHSD(**
Py75c%bn&*)9|fDe^b
DFaq#xzjFr@g5=&nm
dFg$5knvMd’rkvegMs”This is a really long
message about Bill’s…
Asymmetric
Encryption
Message or File Digital Signature128 bits Message Digest
Calculate a short message digest from even a long input using a one-
way message digest function (hash)
Signatory’s private key
private
Verifying a Digital Signature
Jrf843kjf
gf*£$&Hd
if*7oUsd
*&@:<CHD
FHSD(**
Py75c%bn&*)
9|fDe^bDFaq
#xzjFr@g5=
&nmdFg$5kn
vMd’rkvegMs”
Asymmetric
decryption
(e.g. RSA)
Everyone has
access to trusted
public key of the
signatory
Signatory’s
public key
Digital Signature
This is a
really long
message
about Bill’s…
Same hash function
(e.g. MD5, SHA…)
Original Message
Py75c%bn&*)
9|fDe^bDFaq
#xzjFr@g5=
&nmdFg$5kn
vMd’rkvegMs”
? == ?Are They Same?
23
Certificate:
body of data placed in a message to serve as
Proof of the sender’s authenticity.
consists of encrypted information that associates
a public key with the true identity of an individual
Includes the identification and electronic signature of
Certificate Authority (CA).
Includes serial number and period of time when the
certificate is Valid
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Certificate Authority :
trusted organization that issues certificates for
both servers and clients.
create digital certificates that
securely bind the names of users to
their public keys.
Two types of CA:
* Commercial CA
* Self-certified private CA
Typ es of cer t if ica t es
Root
CERT
eeeee
SERVER
CERT
CLIENT
CERT
OBJECT
SIGNING
CERT
OBJECT
CERT
