Subject: DataEncipherment

From: Carlos González-Cadenas <[email-masked]>
Date: Wed, 5 May 2004 15:54:26 +0200

Hi,

Just a question about keyUsage DataEncipherment.

In a RSA-based certificate (the public key included is coming from a RSA key
pair), If I assert the DataEncipherment key usage, I’m telling to the
relying third parties that my certificate (the public key included into) can
be used for raw data encipherment, but, in the reality, RSA algorithm cannot
be used to cipher large amounts of data (as opposed to a symmetric key, in,
for example, a CBC mode). The common technique with that is to use the
keyEncipherment bit to be able to cipher the symmetric session key used to
cipher the raw data.

Can anyone point me to the right direction, or provide me some links to
technical documentation, about real-life usages with the Data Encipherment
key usage??. Are there any other technologies/algorithms for RSA where this
key usage has more sense??.

Thank you very much in advance

Carlos

Carlos González-Cadenas
Jefe de Departamento de Arquitectura Software
Software Architecture Department Manager
Responsable de Seguridad de la Información
Information Security Responsible

e-xtendforce
by e-xtendnow BancSabadell

C/Sena,12 nucli C planta 2
Edifici Landscape
08190 Sant Cugat del Vallès
phone: +34933556139
fax: +34933556142
mailto:  <mailto:[email-masked]>
[email-masked]

Advertencia legal:
Este mensaje y, en su caso, los ficheros anexos son confidenciales,
especialmente en lo que respecta a los datos personales, y se dirigen
exclusivamente al destinatario referenciado. Si usted no lo es y lo ha
recibido por error o tiene conocimiento del mismo por cualquier motivo, le
rogamos que nos lo comunique por este medio y proceda a destruirlo o borrarlo,
y que en todo caso se abstenga de utilizar, reproducir, alterar, archivar o
comunicar a terceros el presente mensaje y ficheros anexos, todo ello bajo pena
de incurrir en responsabilidades legales. El emisor no garantiza la integridad,
rapidez o seguridad del presente correo, ni se responsabiliza de posibles
perjuicios derivados de la captura, incorporaciones de virus o cualesquiera
otras manipulaciones efectuadas por terceros.

Advertiment legal:
Aquest missatge i, si escau, els fitxers annexos tenen caire confidencial,
especialment pel que fa a les dades personals, i s'adrecen exclusivament al
destinatari referenciat. Si no es tracta d'aquest i l'ha rebut per error o se li
ha fet arribar per qualsevol motiu, li preguem que ens ho comuniqui per aquesta
mateixa via i el destrueixi o l'esborri, i que en tot cas s'abstingui d'utilitzar,
reproduir, alterar, arxivar o comunicar a tercers aquest missatge i fitxers
annexos, tot sota pena d'entrar en responsabilitats legals. L'emissor no garanteix
la integritat, la rapidesa o la seguretat d'aquest correu, ni es responsabilitza
de possibles perjudicis derivats de la captura, incorporacions de virus o
qualsevol altres manipulacions que facin tercers.

Disclaimer:
This message and any attached files transmitted with it, is confidential,
especially as regards personal data. It is intended solely for the use of the
individual or entity to whom it is addressed. If you are not the intended recipient
and have received this information in error or have accessed it for any reason,
please notify us of this fact by email reply and then destroy or delete the message,
refraining from any reproduction, use, alteration, filing or communication to third
parties of this message and attached files on penalty of incurring legal
responsibilities. The sender does not guarantee the integrity, the accuracy, the
swift delivery or the security of this email transmission, and assumes no
responsibility for any possible damage incurred through data capture, virus
incorporation or any manipulation carried out by third parties.