McAfee MEJCAE-AM-DA Product Guide - Page 65

Encrypting and signing, Encrypting and wiping the original plaintext file

Page 65 highlights

Encrypting and Decrypting Encrypting information The recipient decrypts the ciphertext with their secret key and passphrase; the plaintext is displayed on the recipient's screen but is not saved to disk. The text is displayed as it would if the recipient used the UNIX "more" command, one screen at a time. If the recipient wants to read the message again, he or she must decrypt the ciphertext a second time. This feature is the safest way for you to prevent your sensitive message from being inadvertently left on the recipient's disk. Note: This feature does not prevent a clever and determined person from finding a way to save the decrypted plaintext to disk-it is designed to help prevent a casual user from doing it inadvertently. Encrypting and signing To digitally sign a file and encrypt it in the same operation, add the --sign option to the command line. E-Business Server signs the message before encrypting it. The signing key specified by the DEFAULT-KEY parameter in the E-Business Server configuration file is used unless you specify a different signing key with the --sign-with modifier. ebs --encrypt --sign --user For example: ebs --encrypt --wipe confidential.txt --user mjohnson This instructs E-Business Server to create a ciphertext file confidential.pgp and to destroy the plaintext file confidential.txt. Note that this option will not wipe out any fragments of plaintext that your word processor might have created on the disk while you were editing the message before running E-Business Server. Most word processors create backup files, scratch files, or both. By default, E-Business Server overwrites the file three times. If you want to specify the number of times E-Business Server overwrites the file, and not use the default, add the --wipe-passes modifier. ebs --encrypt --wipe --user

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63
E-Business Server
8.6
Product Guide
Encrypting and Decrypting
Encrypting information
The recipient decrypts the ciphertext with their secret key and passphrase; the plaintext is displayed on the
recipient’s screen but is not saved to disk. The text is displayed as it would if the recipient used the UNIX
“more” command, one screen at a time. If the recipient wants to read the message again, he or she must
decrypt the ciphertext a second time.
This feature is the safest way for you to prevent your sensitive message from being inadvertently left on the
recipient’s disk.
Note:
This feature does not prevent a clever and determined person from finding a way to save the decrypted plaintext
to disk—it is designed to help prevent a casual user from doing it inadvertently.
Encrypting and signing
To digitally sign a file and encrypt it in the same operation, add the
--sign
option to the command line.
E-Business Server signs the message before encrypting it. The signing key specified by the
DEFAULT-KEY
parameter in the E-Business Server configuration file is used unless you specify a different signing key with
the
--sign-with
modifier.
ebs --encrypt --sign <plaintext_filename> --user <recipient’s_userID> [--sign-with <your_userID>]
For example:
ebs --encrypt --sign testresults.doc --user “Jennifer Quino” --sign-with “Anita Brown”
Encrypting and wiping the original plaintext file
To wipe the original plaintext file, overwriting and deleting it completely, then add the
--wipe
option to the
encryption operation.
ebs --encrypt --wipe <plaintext_filename> --user <recipient’s_userID>
For example:
ebs --encrypt --wipe confidential.txt --user mjohnson
This instructs E-Business Server to create a ciphertext file
confidential.pgp
and to destroy the plaintext file
confidential.txt
.
Note that this option will not wipe out any fragments of plaintext that your word processor might have
created on the disk while you were editing the message before running E-Business Server. Most word
processors create backup files, scratch files, or both.
By default, E-Business Server overwrites the file three times. If you want to specify the number of times
E-Business Server overwrites the file, and not use the default, add the
--wipe-passes
modifier.
ebs --encrypt --wipe <plaintext_filename> --user <recipient’s_userID> --wipe-passes <number of times>
Creating Self-Decrypting Archives (SDAs)
You can use E-Business Server to create a self-decrypting executable file, which is conventionally encrypted
using a passphrase that you are asked to choose. The resulting executable file can be decrypted by simply
double-clicking on it and entering the appropriate passphrase. This option is especially convenient for users
who are sending encrypted files to people who do not have E-Business Server software installed.
Note:
The final SDA cannot be larger than 4 GB in size. The input may be larger than 4 GB if E-Business Server can
compress it to a size smaller than 4 GB.
Note:
While you can create SDAs on any platform E-Business Server supports, SDAs will execute only on Windows
platforms—Windows 95, 98, NT, and 2000. See
Creating PGParchives
on page 64
for a cross-platform alternative.
To create an SDA, you simply add the
--sda
(self-decrypting archive) modifier to the
--encrypt
option. You
must also specify the name of the input file.
ebs --encrypt --sda <filename>
Optionally, you can specify more than one input file, the name of the output file, and the passphrase you
want to use for the conventional encryption.