One feature of Windows NT/2000's (Win2K) C2-compliance is that itimplements object reuse protection. This means that when an applicationallocates file space or virtual memory it is unable to view data thatwas previously stored in the resources Windows NT/2K allocates for it.Windows NT zero-fills memory and zeroes the sectors on disk where a fileis placed before it presents either type of resource to an application.However, object reuse does not dictate that the space that a fileoccupies before it is deleted be zeroed. This is because Windows NT/2Kis designed with the assumption that the operating system controlsaccess to system resources. However, when the operating system is notactive it is possible to use raw disk editors and recovery tools to viewand recover data that the operating system has deallocated. Even whenyou encrypt files with Win2K's Encrypting File System (EFS), a file'soriginal unencrypted file data is left on the disk after a new encryptedversion of the file is created.
The only way to ensure that deleted files, as well as files that youencrypt with EFS, are safe from recovery is to use a secure deleteapplication. Secure delete applications overwrite a deleted file'son-disk data using techniques that are shown to make disk dataunrecoverable, even using recovery technology that can read patterns inmagnetic media that reveal weakly deleted files. SDelete (SecureDelete) is such an application. You can use SDelete both to securelydelete existing files, as well as to securely erase any file data thatexists in the unallocated portions of a disk (including files that youhave already deleted or encrypted). SDelete implements the Departmentof Defense clearing and sanitizing standard DOD 5220.22-M, to give youconfidence that once deleted with SDelete, your file data is goneforever. Note that SDelete securely deletes file data, but not filenames located in free disk space.
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Securely deleting a file that has no special attributes is relativelystraight-forward: the secure delete program simply overwrites the filewith the secure delete pattern. What is more tricky is securely deletingWindows NT/2K compressed, encrypted and sparse files, and securelycleansing disk free spaces.
Compressed, encrypted and sparse are managed by NTFS in 16-clusterblocks. If a program writes to an existing portion of such a file NTFSallocates new space on the disk to store the new data and after the newdata has been written, deallocates the clusters previously occupied bythe file. NTFS takes this conservative approach for reasons related todata integrity, and in the case of compressed and sparse files, in casea new allocation is larger than what exists (the new compressed data isbigger than the old compressed data). Thus, overwriting such a file willnot succeed in deleting the file's contents from the disk.
To handle these types of files SDelete relies on the defragmentationAPI. Using the defragmentation API, SDelete can determine preciselywhich clusters on a disk are occupied by data belonging to compressed,sparse and encrypted files. Once SDelete knows which clusters containthe file's data, it can open the disk for raw access and overwrite thoseclusters.
Cleaning free space presents another challenge. Since FAT and NTFSprovide no means for an application to directly address free space,SDelete has one of two options. The first is that it can, like it doesfor compressed, sparse and encrypted files, open the disk for raw accessand overwrite the free space. This approach suffers from a big problem:even if SDelete were coded to be fully capable of calculating the freespace portions of NTFS and FAT drives (something that's not trivial), itwould run the risk of collision with active file operations taking placeon the system. For example, say SDelete determines that a cluster isfree, and just at that moment the file system driver (FAT, NTFS) decidesto allocate the cluster for a file that another application ismodifying. The file system driver writes the new data to the cluster,and then SDelete comes along and overwrites the freshly written data:the file's new data is gone. The problem is even worse if the cluster isallocated for file system metadata since SDelete will corrupt the filesystem's on-disk structures.
On NTFS drives SDelete's job isn't necessarily through after itallocates and overwrites the two files. SDelete must also fill anyexisting free portions of the NTFS MFT (Master File Table) with filesthat fit within an MFT record. An MFT record is typically 1KB in size,and every file or directory on a disk requires at least one MFT record.Small files are stored entirely within their MFT record, while filesthat don't fit within a record are allocated clusters outside the MFT.All SDelete has to do to take care of the free MFT space is allocatethe largest file it can - when the file occupies all the available spacein an MFT Record NTFS will prevent the file from getting larger, sincethere are no free clusters left on the disk (they are being held by thetwo files SDelete previously allocated). SDelete then repeats theprocess. When SDelete can no longer even create a new file, it knowsthat all the previously free records in the MFT have been completelyfilled with securely overwritten files.
The site is secure. The ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.
The FortiGate uses the HMAC based on the authentication proposal that is chosen in phase 1 or phase 2 of the IPsec configuration. Each proposal consists of the encryption-hash pair (such as 3des-sha256). The FortiGate matches the most secure proposal to negotiate with the peer.
Transport Layer Security (TLS) encrypts data sent over the Internet to ensure that eavesdroppers and hackers are unable to see what you transmit which is particularly useful for private and sensitive information such as passwords, credit card numbers, and personal correspondence. This page explains what TLS is, how it works, and why you should deploy it.
TLS is normally implemented on top of TCP in order to encrypt Application Layer protocols such as HTTP, FTP, SMTP and IMAP, although it can also be implemented on UDP, DCCP and SCTP as well (e.g. for VPN and SIP-based application uses). This is known as Datagram Transport Layer Security (DTLS) and is specified in RFCs 6347, 5238 and 6083.
Data has historically been transmitted unencrypted over the Internet, and where encryption was used, it was typically employed in a piecemeal fashion for sensitive information such as passwords or payment details. Whilst it was recognised back in 1996 (by RFC 1984) that the growth of the Internet would require private data to be protected, it has become increasingly apparent over the intervening period that the capabilities of eavesdroppers and attackers are greater and more pervasive than previously thought. The IAB therefore released a statement in November 2014 calling on protocol designers, developers, and operators to make encryption the norm for Internet traffic, which essentially means making it confidential by default.
Without TLS, sensitive information such as logins, credit card details and personal details can easily be gleaned by others, but also browsing habits, e-mail correspondence, online chats and conferencing calls can be monitored. By enabling client and server applications to support TLS, it ensures that data transmitted between them is encrypted with secure algorithms and not viewable by third parties.
Recent versions of all major web browsers currently support TLS, and it is increasingly common for web servers to support TLS by default. However, use of TLS for e-mail and certain other applications is still often not mandatory, and unlike with web browsers that provide visual clues, it is not always apparent to users whether their connections are encrypted.
With symmetric cryptography, data is encrypted and decrypted with a secret key known to both sender and recipient; typically 128 but preferably 256 bits in length (anything less than 80 bits is now considered insecure). Symmetric cryptography is efficient in terms of computation, but having a common secret key means it needs to be shared in a secure manner.
The advantage of asymmetric cryptography is that the process of sharing encryption keys does not have to be secure, but the mathematical relationship between public and private keys means that much larger key sizes are required. The recommended minimum key length is 1024 bits, with 2048 bits preferred, but this is up to a thousand times more computationally intensive than symmetric keys of equivalent strength (e.g. a 2048-bit asymmetric key is approximately equivalent to a 112-bit symmetric key) and makes asymmetric encryption too slow for many purposes.
For this reason, TLS uses asymmetric cryptography for securely generating and exchanging a session key. The session key is then used for encrypting the data transmitted by one party, and for decrypting the data received at the other end. Once the session is over, the session key is discarded.
Health Information Exchange (HIE) is the mobilization of health care information electronically across organizations within a region, community or hospital system. HIE provides the capability to electronically move clinical information among different health care information systems.
This information is collected in NPPES to facilitate the electronic exchange of health care information such as Medical records, order and referrals, etc., in a safe and secure fashion. Providers are encouraged to enter Endpoint information in NPPES to promote interoperability in health care, however, this information is not required to obtain an NPI. Providers can still obtain an NPI without providing such information. 2ff7e9595c
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