XCERT Software, Inc.

This article gives an overview of public key infrastructure (PKI) technology, which uses digital certificates, and some usage models and it introduces some important system-design considerations for building safe and secure services on networks using PKI.Although PKI is a common security technology, the concepts and considerations required when applying it to practical systems are not widely understood.

Public Key Infrastructures: A Panacea Solution?

Secure automated request processing software for DataGrid certification authorities

Digital certificates: worth the paper they're written on?

A Public Key Infrastructure (PKI) is considered one of the most important techniques used to propagate trust in authentication over the Internet. This technology is based on a trust model defined by the original X.509 (1988) standard and is composed of three entities: the certification authority (CA), the certificate holder (or subject), and the Relying Party (RP). The CA plays the role of a trusted third party between the certificate holder and the RP. In many use cases, this trust model has worked successfully. However, we argue that the application of this model on the Internet implies that web users need to depend on almost anyone in the world in order to use PKI technology. Thus, we believe that the current TLS system is not fit for purpose and must be revisited as a whole. In response, the latest draft edition of X.509 has proposed a new trust model by adding new entity called the Trust Broker (TB). In this paper, we present an implementation approach that a Trust Broker could follow in order to give RPs trust information about a CA by assessing the quality of its issued certificates. This is related to the quality of the CA’s policies and procedures and its commitment to them. Finally, we present our Trust Broker implementation that demonstrates how RPs can make informed decisions about certificate holders in the context of the global web, without requiring large processing resources themselves.


 
 
 History of Seal and Printing Cultures Implications of the four important Chinese inventions, the compass, gun powder, papermaking, and printing, have far-reaching significance for human civilisation. The Chinese seal is intimately related to printing. Seals have the practical function of duplicating impressions of words or patterns. This process shares a very similar concept to printing on a small scale. Printing originated from the function of seals for making duplicated impressions, and for this reason Wang believes that seals constitute the prototype of printing. Seals in Traditional Commere Seals in certain Asian countries, such as Taiwan and Japan, play a vital role similar to that played by signatures in Western society. Particularly, the Chinese seal has been an integral part of Chinese heritage and culture. Wong states that seals usually symbolise tokens of promise in Chinese society. Ancient seals in their various forms have played a major role in information systems, in terms of authority, authentication, identification, certified proof, and authenticity, and have also been used for tamper-proofing, impression duplication, and branding purposes. To illustrate, clay sealing has been applied to folded documents to detect when sealed documents have been exposed or tampered with. Interestingly, one of the features of digital signature technology is also designed to achieve this purpose. Wong records that when the commodity economy began to develop and business transactions became more frequent, seals were used to prove that particular goods had been certified by customs. Moreover, when the goods were subject to tax by the government, seals were applied to the goods to prove the levy paid. Seals continue to be used in Chinese society as personal identification and in business transactions, official and legal documents, administrative warrants and charters. Paper-based Contract Signing with Seal Certificates In Taiwan and Japan, in certain circumstances, when two parties wish to formalise a contract, the seals of the two parties must be affixed to the contract. As Figure 1 illustrates, seal certificates are required to be attached to the signed and sealed contract for authentication as well as the statement of intent of a voluntary agreement in Taiwan. Figure 1. Example of a contract attached with the seal certificates A person can have more than one seal; however, only one seal at a time is allowed to be registered with a jurisdictional registration authority. The purpose of seal registration is to prevent seal forgery and to prove the identity of the seal owner. Namely, the seal registration process aims to associate the identity of the seal owner with the seal owner’s nominated seal, through attestation by a jurisdictional registration authority. Upon confirmation of the seal registration, the registration authority issues a seal certificate with both the seals of the registration authority and the registration authority executive. Digital Signatures for Electronic Commerce Handwritten signatures and tangible ink seals are highly impractical within the electronic commerce environment. However, the shift towards electronic commerce by both the public and private sector is an inevitable trend. ‘Trust’ in electronic commerce is developed through the use of ‘digital signatures’ in conjunction with a trustworthy environment. In principle, digital signatures are designed to simulate the functions of handwritten signatures and traditional seals for the purposes of authentication, data integrity, and non-repudiation within the electronic commerce environment. Various forms of Public Key Infrastructure (PKI) are employed to ensure the reliability of using digital signatures so as to ensure the integrity of the message. PKI does not, however, contribute in any way to the signatory’s ability to verify and approve the content of an electronic document prior to the affixation of his/her digital signature. Shortcomings of Digital Signature Scheme One of the primary problems with existing digital signatures is that a digital signature does not ’feel’ like, or resemble, a traditional seal or signature to the human observer; it does not have a recognisably individual or aesthetic quality. Historically, the authenticity of documents has always been verified by visual examination of the document. Often in legal proceedings, examination of both the affixed signature or seal as an integral part of the document will occur, as well as the detection of any possible modifications to the document. Yet, the current digital signature regime overlooks the importance of this sense of visualisation. Currently, digital signatures, such as the OpenPGP (Pretty Good Privacy) digital signature, are appended to an electronic document as a long, incomprehensible string of arbitrary characters. As shown in Figure 2, this offers no sense of identity or ownership by simple visual inspection. Figure 2. Example of a PGP signature To add to this confusion for the user, a digital signature will be different each time the user applies it. The usual digital signature is formed as an amalgam of the contents of the digital document and the user’s private key, meaning that a digital signature attached to an electronic document will vary with each document. This again represents a departure from the traditional use of the term ‘signature’. A digital signature application generates its output by firstly applying a hash algorithm over the contents of the digital document and then encrypting that hash output value using the user’s private cryptographic key of the normal dual-key pair provided by the Public Key cryptography systems. Therefore, digital signatures are not like traditional signatures which an individual can identify as being uniquely theirs, or as a recognisable identity attributable to an individual entity. New Visualised Digital Signature Scheme Liu et al. have developed the visualised digital signature scheme to enhance existing digital signature schemes through visualisation; namely, this scheme makes the intangible digital signature virtually tangible. Liu et al.’s work employs the visualised digital signature scheme with the aim of developing visualised signing and verification in electronic situations. The visualised digital signature scheme is sustained by the digital certificate containing both the certificate issuer’s and potential signer’s seal images. This thereby facilitates verification of a signer’s seal by reference to the appropriate certificate. The mechanism of ensuring the integrity and authenticity of seal images is to incorporate the signer’s seal image into an X.509 v3 certificate, as outlined in RFC 3280. Thus, visualised digital signature applications will be able to accept the visualised digital certificate for use. The data structure format of the visualised digital certificate is detailed in Liu. The visualised signing and verification processes are intended to simulate traditional signing techniques incorporating visualisation. When the signer is signing the document, the user interface of the electronic contracting application should allow the signer to insert the seal from the seal image file location into the document. After the seal image object is embedded in the document, the document is referred to as a ’visually sealed’ document. The sealed document is ready to be submitted to the digital signing process, to be transmitted with the signer’s digital certificate to the other party for verification. The visualised signature verification process is analogous to the traditional, sealed paper-based document with the seal certificate attached for verification. In history, documents have always required visual stimulus for verification, which highlights the need for visual stimulus evidence to rapidly facilitate verification. The user interface of the electronic contracting application should display the visually sealed document together with the associated digital certificate for human verification. The verifier immediately perceives the claimed signer’s seal on the document, particularly when the signer’s seal is recognisable to the verifier. This would be the case particularity where regular business transactions between parties occur. Significantly, having both the issuing CA’s and the signer’s seal images on the digital certificate instils confidence that the signer’s public key is attested to by the CA, as shown in Figure 3. This is unlike the current digital signature verification process which presents long, meaningless strings to the verifier. Figure 3. Example of a new digital certificate presentation Conclusions Seals have a long history accompanying the civilisation of mankind. In particular, certain business documents and government communities within seal-culture societies still require the imprints of the participating entities. Inevitably, the use of modern technologies will replace traditional seals and handwritten signatures. Many involved in implementing electronic government services and electronic commerce care little about the absence of imprints and/or signatures; however, there is concern that the population may experience difficulty in adapting to a new electronic commerce system where traditional practices have become obsolete. The purpose of the visualised digital signature scheme is to explore enhancements to existing digital signature schemes through the integration of culturally relevant features. This article highlights the experience of the use and development of Chinese seals, particularly in visualised seals used in a recognition process. Importantly, seals in their various forms have played a major role in information systems for thousands of years. In the advent of the electronic commerce, seal cultures still remain in the d

Certificate Authorities (CAs) are important components for digital certificate issuances in Public Key Infrastructure(PKI). However, current CAs have some intrinsic weaknesses due to the CA-centric implementation. And when browser and operating system vendors contain a CA in the software, they place complete trust in the CA. In this paper, we utilize natural characteristics of tamper-proof and transparency of smart contracts in blockchain platforms to design an independent entity, named the CA proxy, to manage life cycle of digital certificates. This management will achieve the certificate transparency. We propose a new system architecture easy to integrate the CA proxy with current CAs through applying the blockchain oracle service. In this architecture, the CA proxy, CAs, and even professional identity verification parties can accomplish life cycle management of certificates, signature of certificates, identity verification for certificates correspondingly. The achievement of the certificate transparency through life cycle management of digital certificates in blockchain platforms, when compared with traditional CAs, solves traditional CAs' trust model weaknesses and improve the security.

Public-Key Infrastructure (PKI) provides robust and scalable security services like authentication and non-repudiation using digital certificates. An efficient key management is necessary for a long term implementation of PKI. As a part of key management, key pair of all the entities within the PKI system is updated regularly to minimize overuse of keys and to comply with the organization's policies. In a hierarchical PKI system, root Certificate Authority (CA) is the highest trust anchor and hence updating its key pair is a challenging task. It requires proper authentication of certificate issuing entities to its subordinates and storage of keys for future reference. This paper discusses the various mechanisms available for updating root CA key pairs and brings out pros and cons in each. Considering the shortcomings of these methods, a new method for key pair update has been proposed, which is less complex and easy to implement. In addition, some of the open-source tools available to implement these techniques and open challenges which need to be addressed to have been highlighted.

PKI(Public Key Infrastructure) provides confidentiality, integrity, and non-repudiation services for etransaction and various countries around the world offer a e-commerce service by using PKI. These PKI technologies can be used in e-transaction between countries like e-trade area. To do this, an interoperability of PKI technology is necessary between different PKI domains. This paper introduces „Asia PKI Interoperability Guideline“ that was developed by the pilot project between Asia countries for Asia PKI interoperability and intends to present the possibility of PKI interoperability between countries.

The Web public-key infrastructure (PKI) provides a mechanism to identify websites to end users for the purposes of encrypted communication. The security of the Web PKI primarily relies on certification authorities (CAs), trusted parties whose misbehavior can enable man-in-the-middle (MITM) attacks: the impersonation of websites to users, followed by the theft or modification of sensitive information. While many methods of addressing CA misbehavior have been proposed, no solution has been both effective and practical: able to protect websites users against C misbehavior and to be easily deployed and used by all parties involved. Thus, despite more than two decades of research advances, the Web PKI remains largely vulnerable to misbehaving CAs.In this thesis, I argue that we can use minimal changes to existing technology to build deployable solutions thatreduce the rate of successful MITM attacks in the Web PKI. Specifically, I present three projects that exemplifyeffective and practical approaches to improving the Web PKI. In IKP, I use the Ethereum cryptocurrency and smartcontract platform to build an insurance-like mechanism that disincentivizes CA misbehavior. In CAPS, I use twoglobal monitoring and logging systems, CT and Censys, to build a system that strengthens the existing PKI againstmisbehaving CAs and enables the secure incremental deployment of new and improved PKIs for theWeb. In SAINT, I use the SCION future Internet architecture to propose a PKI that unifies public-key authentication for naming, routing, and end-entity public keys in a federated environment, and identify challenges and desired properties in such an environment. Through this work, I provide a first step towards making a more resilient Web PKI a reality.

In public-key encryption, the secrecy of the public key is not required, but the authenticity of the public key is necessary to guarantee its integrity and to avoid spoofing and playback attacks. A user’s public key can be authenticated (signed) by a certificate authority that verifies that a public key belongs to a specific user. In this chapter, digital certificates, which are used to validate public keys, and certificate authorities are discussed. When public-key is used, it is necessary to have a comprehensive system that provides public key encryption and digital signature services to ensure confidentiality, access control, data integrity, authentication, and non-repudiation. That system, public-key infrastructure or PKI, is also discussed in this chapter.

Basic Security Concepts - Why is Computer and Network Security Important. Background and History. The Security Trinity. Information Security. Risk Assessment. Security Models. Basic Terminology. More Basic Terminology. Threats, Vulnerabilities and Attacks - Protocols. The OSI Reference Model. TCP/IP Protocol Suite. Useful Web Sites. Search Engines. Mailing Lists. Encryption, Digital Signatures and Certification - Cryptography. Stream Ciphers. Breaking Ciphers. Block Ciphers. Encryption. Public Key Cryptosystems. Message Integrity. Authentication. Digital Signatures. Competing Standards. Digital Certificates. Limitations of Digital Certificates. Certificate Authorities. Public Key Infrastructure. The Future. The Limitations of Encryption. Kerberos - How Kerberos Works. Kerberos- Limitations. Encryption on the WWW - The World Wide Web. Secure Sockets Layer (HTTPS). Secure HTTP (SHTTP). Microsoft's Internet Explorer. Viewing Digital Certificates with Internet Explorer. Viewing the Encryption Strength of IE5. Viewing Certification Authorities with IE5. Netscape Navigator. Viewing Digital Certificates with Navigator. Authenticode Certificates. E-Mail - E-Mail Issues. E-Mail Issues. Secure E-Mail Protocols. Web-Based E-Mail Services. Security of Stored Messages. Identity: Spoofing and Hiding. E-Mail as a weapon. E-Mail Policies. E-Mail Privacy. Auto-Responses. Operating System Security -- Passwords. Password Attacks. Onetime Passwords. Access Control. Data Redundancy. General Recommendations. Modems. Useful Tools. LAN Security - LAN Guidelines. Controlling End-User Access. Concurrent Logins. Available Disk Space. Restrictions to Location or Workstation. Time/Day Restrictions. Access to Directories and Trustee Rights. File Attributes. Other Privileges. Single Sign-On. Policy-Based Network Management. Honeypot Systems. Network Segmentation. Static IP Addresses vs. DHCP. Media and Protocols - Network Media. Plenum Cabling and Risers. WANs. Redundancy and Alternative Connections. Routers and SNMP - Router Issues. SNMP. Virtual Private Networks - Encryption on the Network. Node-to-Node Encryption. End-to-End Encryption. Where to Encrypt. Virtual Private Networks. PPTP. L2TP. IPSec. SOCKS. Firewalls - Firewalls Pros and Cons. Types of Firewalls. Packet Filters vs. Proxies. Firewall Configurations. Restricting Users' Access to the Internet. Firewall Products. Personal Firewalls. Biometrics - Identification and Authentication. Biometric Identification and Authentication. Biometric Identification Reliability. Backup Authentication. Environmental Conditions. User Acceptance. Security of the Biometric System. Interoperability. Costs vs. Savings. Policies and Procedures - Policies vs. Procedures. Information Security Policy Objectives. Developing Security Policies. Policy and Procedure Manuals. Policy Awareness & Education. Policy Enforcement. Policy Format. Security Policy Suggestions. Information Protection Team. Crisis Management Planning. Sources for Information Policies. Auditing and Intrusion Detection - What is an Audit. Operational Security Audits. System Security Auditing. Activity and Usage Auditing. Audit Mistakes. Deficiencies of Traditional Audit Techniques. Intrusion Detection. Intrusion Detection Systems. Host-Based Intrusion Detection Systems. Network-Based Intrusion Detection Systems. Knowledge-Based Intrusion Detection Systems. Statistical-Based Intrusion Detection Systems. Defense In-Depth Approach . Future Directions. Crisis Management Planning - Crisis Management. Disaster Recovery Planning. Computer Security Incident Response Plan. Browser Security - Cookie Files. Cache Files. Autocomplete.

Traditionally, a Certification Authority (CA) is required to sign, manage, verify and revoke public key certificates. Multiple CAs together form the CA-based Public Key Infrastructure (PKI). The use of a PKI forces one to place trust in the CAs, which have proven to be a single point-of-failure on multiple occasions. Blockchain has emerged as a transformational technology that replaces centralized trusted third parties with a decentralized, publicly verifiable, peer-to-peer data store which maintains data integrity among nodes through various consensus protocols. In this paper, we deploy three blockchain-based alternatives to the CA-based PKI for supporting IoT devices, based on Emercoin Name Value Service (NVS), smart contracts by Ethereum blockchain, and Ethereum Light Sync client. We compare these approaches with CA-based PKI and show that they are much more efficient in terms of computational and storage requirements in addition to providing a more robust and scalable PKI.

CA (Certificate Authority) acts as the trusted third party, which serves to issue digital certificates and validate them in PKI (Public Key Infrastructure). Hence it's significant to ensure the CA system's security. The ECC (Elliptic Curve Cryptography) has the advantages of shorter key and higher efficiency, comparing with other public key cryptographies such as RSA. The purpose of this work is to design and implement a CA based on ECC by using Java programming technique, which can sign X.509v3 digital certificate to client and then validate client certificate. In application, the key pair (including public key and private key) can be got from the PKCS#12 (Public Key Cryptography Standard), which is used in encryption, decryption and digital signature. The ECC-based CA is used in the system of DRM (Digital Rights Management) to contribute to confidentiality, authenticity, integrality and non-repudiation in communication.

Modern Internet TCP uses Secure Sockets Layers (SSL)/Transport Layer Security (TLS) for secure communication, which relies on Public Key Infrastructure (PKIs) to authenticate public keys. Conventional PKI is done by Certification Authorities (CAs), issuing and storing Digital Certificates, which are public keys of users with the users identity. This leads to centralization of authority with the CAs and the storage of CAs being vulnerable and imposes a security concern. There have been instances in the past where CAs have issued rogue certificates or the CAs have been hacked to issue malicious certificates. Motivated from these facts, in this paper, we propose a method (named as Trustful), which aims to build a decentralized PKI using blockchain. Blockchains provide immutable storage in a decentralized manner and allows us to write smart contracts. Ethereum blockchain can be used to build a web of trust model where users can publish attributes, validate attributes about other users by signing them and creating a trust store of users that they trust. Trustful works on the Web-of-Trust (WoT) model and allows for any entity on the network to verify attributes about any other entity through a trusted network. This provides an alternative to the conventional CA-based identity verification model. The proposed model has been implemented and tested for efficacy and known major security attacks.