Securing e Government Securing e Government Public Key Public Key Infrastructure Infrastructure Prof Dr Mohamed Kouta Prof Dr Mohamed Kouta Chairman Of MIS Department Chairman Of MIS Department Arab Academy For Science And Technology Arab Academy For Science And Technology
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Securing e Government Public Key Infrastructure Prof Dr Mohamed Kouta Chairman Of MIS Department Arab Academy For Science And Technology.
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Securing e GovernmentSecuring e GovernmentPublic Key InfrastructurePublic Key Infrastructure
Prof Dr Mohamed KoutaProf Dr Mohamed KoutaChairman Of MIS DepartmentChairman Of MIS Department
Arab Academy For Science And TechnologyArab Academy For Science And Technology
OutlineOutline
Security Requirements.Security Requirements. Symmetric Key Cryptosystem.Symmetric Key Cryptosystem. Asymmetric (Public) Key Cryptosystem.Asymmetric (Public) Key Cryptosystem. Over View of Digital Signature.Over View of Digital Signature. Secure Socket Layer Protocol.Secure Socket Layer Protocol. Digital Certificate.Digital Certificate. Certificate Authority.Certificate Authority. PKI Components.PKI Components. PKI Implementation.PKI Implementation. Using biometrics and Smart Token.Using biometrics and Smart Token. PKI Assessment.PKI Assessment.
Security RequirementsSecurity Requirements
Privacy.Privacy. Authenticity.Authenticity. Non repudiationNon repudiation Integrity.Integrity.
X509 StandardX509 StandardEach certificate contains theEach certificate contains the
public-key of a user and is signedpublic-key of a user and is signed
with the private-key of a trusted with the private-key of a trusted
certificate authoritycertificate authority
CertificateCertificate AuthorityAuthority
In an uncontrolled system, anyone could publish a In an uncontrolled system, anyone could publish a new public-key and assume a new identity.new public-key and assume a new identity.
Any Participant can send his public-key to any other Any Participant can send his public-key to any other one broadcast the keyone broadcast the key
CertificateCertificate AuthorityAuthority
This would be like allowing anyone to issue his or This would be like allowing anyone to issue his or her own passport or driving licensesher own passport or driving licenses
This is clearly unacceptable for any application that, This is clearly unacceptable for any application that, like electronic commerce, requires authentication like electronic commerce, requires authentication and non-repudiation.and non-repudiation.
In order to assure a proper information exchange In order to assure a proper information exchange mechanism, an important entity should be involved mechanism, an important entity should be involved in the process which is the Certificate Authority in the process which is the Certificate Authority (CA).(CA).
CertificateCertificate AuthorityAuthority
Cont. Distribution of Public KeysCont. Distribution of Public Keys
Public key CertificatePublic key Certificate
CertificateCertificate AuthorityAuthority
Requirements of setting up the CARequirements of setting up the CA1.1. Compatibility with existing Internet based Certificate Compatibility with existing Internet based Certificate
AuthoritiesAuthorities It should be possible to use the certificates in It should be possible to use the certificates in
applications such as Netscape navigators, secure email, applications such as Netscape navigators, secure email, and custom built business-to-business e-commerce and custom built business-to-business e-commerce applications.applications.
Certificates must be consistent with accepted Certificates must be consistent with accepted standards; such the widely recognized X.509 standards; such the widely recognized X.509 certificate formats.certificate formats.
Certificate AuthorityCertificate Authority
Effective Distribution mechanismsEffective Distribution mechanisms Directory server support:-Directory server support:-
includes client certificates, and certificate validity includes client certificates, and certificate validity status.status.
Certificates accompanying signatures:-Certificates accompanying signatures:- The certificate, being signed by the ECA, enables the The certificate, being signed by the ECA, enables the
receiving party to check the validity of both the receiving party to check the validity of both the certificate, and the accompanying signature.certificate, and the accompanying signature.
Support for certificate revocation:-Support for certificate revocation:-
Certificate AuthorityCertificate Authority
Revocation of Revocation of CertificatesCertificates The user’s private key The user’s private key
is compromisedis compromised The user is no longer The user is no longer
certified by this CAcertified by this CA The CA’s certificate is The CA’s certificate is
Some time later the user wants to revoke the certificate…
Revocation requestCertificate is included
in the Certificate Revocation List (CRL)
PKI ComponentPKI Component
Certificate Authority (CA).Certificate Authority (CA). Issues Digital CertificatesIssues Digital Certificates
Authorization Authority (AA).Authorization Authority (AA). Response for Digital Certificate (DC) requestResponse for Digital Certificate (DC) request
Registration Authority (RA).Registration Authority (RA). Contains a database for DC and Certificate Revocation ListContains a database for DC and Certificate Revocation List CRL.CRL.
Directory Services.Directory Services. Handles DC exchange.Handles DC exchange.
Applications.Applications.
PKI ImplementationPKI Implementation
Issuing the Certificate Practice Statement Issuing the Certificate Practice Statement (CPS).(CPS).
A statement of Practices that CA employs in issuing DC.A statement of Practices that CA employs in issuing DC.
Building the PKI as according CPS.Building the PKI as according CPS. Training for users and administration Staff.Training for users and administration Staff. Connections to secured systems that could Connections to secured systems that could
circumvented the PKI must be ended.circumvented the PKI must be ended. Integration with the different applications. Integration with the different applications.
Using Biometrics and Using Biometrics and Smart Token inSmart Token in
Electronic signature Electronic signature
How a citizen can apply for a Smart TokenHow a citizen can apply for a Smart Token Step 1Step 1 The citizen (Applicant A) provides his National Security Number Card (NSN)The citizen (Applicant A) provides his National Security Number Card (NSN) to to
one of the Service Provider (SP).one of the Service Provider (SP). Step 2Step 2 SP sends the NSN information to the CA.SP sends the NSN information to the CA. Step 3Step 3 CA checks for Applicant already has a DC or revoked with RA.CA checks for Applicant already has a DC or revoked with RA. Step 4Step 4 If A is applying first time, CA asks for authorization from AA.If A is applying first time, CA asks for authorization from AA. Step 5Step 5 AA responses for CA.AA responses for CA. Step 6Step 6 CA asks A to generate his keys pair.CA asks A to generate his keys pair. Step 7Step 7 The Two pairs are generated inside the applicant smart Token.The Two pairs are generated inside the applicant smart Token. Step 8Step 8 The public Key is sent to the CA.The public Key is sent to the CA. Step 9Step 9 The CA generates and sends the DC back to the applicant Token.The CA generates and sends the DC back to the applicant Token. Step 10Step 10 The token is trained for the applicant finger print. The token is trained for the applicant finger print.
Sender side Pre Session StagePre Session Stage
CA
2 check validity
Sender (S) Receiver (R)
1 S w
ants
to c
omm
unicat
e w
ith R
3 SDC
3 R
DC
Sender side
ESM + DE
Sender PC
Sender Token
Sender Data
MD
SDS +SDC
1- Selecting the message M to be sent from the sender PC (SPC).
2- According to the Hashing Algorithm (HA) stored in the SPC , M will be hashed and the message digest (MD)
will be generated.
3- The message digest MD is transferred from the SPC to the sender Smart Token (SST).
6- Using a random number generator (RNG), a session key (SK) will be generated inside the SPC.
7- Encrypting M+SDS+SDC using symmetric key encryption algorithm SKEA and Sk as encryption key and call it the encrypted signed message (ESM).
8- Extracting the receiver public key (RPUK) from the RDC available in the SCL.
9- Encrypt the SK with RPUK using PKUK to create Digital Envelop (DE) send ESM+DE.
4- Using public key cryptographic algorithm (PKCA) ,the MD is encrypted with the sender private key (SPRK) to get the sender digital signature (SDS).
5- The SDS+ a copy from the sender digital certificate (SDC) are sent back to the SPC.
Sender side Third ProcessThird Process
Receiver PC
DE
Encrypted Signed message (ESM)Encrypted session keyBy receiver public key (DE)
Sender PC
ESM+
1-DE is sent to the receiver smart token (RST).
4- By the SK the message will be Decrypted using the same SKEA Now we have : M+ SDS + SDC.
5- The SDC received from CA is compared with SDC received from the sender to assure its validity. If its valid the procedure continue , aborted otherwise. 6- Decrypt the SDS by the sender public key SPUK contained in the SDC to get MD. Call it MD1.
8- Using M generate a message digest MD using the same HA. Call it MD2.
7- Compare the two digests MD1 and MD2. If MD1 and MD2 are identical then message accepted otherwise the message is rejected.
Receiver PC
Receiver side
2- Using PKEA the DE is Decrypted by the RPRK to get the session key SK.
• • The presence of undesired spikes and breaks present in a The presence of undesired spikes and breaks present in a thinned ridge map may lead to many spurious thinned ridge map may lead to many spurious minutiae being detected.minutiae being detected.
• • Therefore, before the minutiae detection, a smoothing Therefore, before the minutiae detection, a smoothing procedure is applied to remove spikes and to join procedure is applied to remove spikes and to join broken ridges.broken ridges.